Coding gudilines for class and methods javadocs fixed.

Change-Id: I0153e6391c9ec9eacaac65c3989834b6bf5c65bf
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java
index b6ab595..d315d9b 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java
@@ -75,7 +75,7 @@
 import org.onosproject.yangutils.parser.impl.listeners.VersionListener;
 
 /**
- * ANTLR generates a parse-tree listener interface that responds to events
+ * Represents ANTLR generates parse-tree. ANTLR generates a parse-tree listener interface that responds to events
  * triggered by the built-in tree walker. The methods in listener are just
  * callbacks. This class implements listener interface and generates the
  * corresponding data model tree.
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/YangUtilsParserManager.java b/src/main/java/org/onosproject/yangutils/parser/impl/YangUtilsParserManager.java
index d17cb4e..a1fffb8 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/YangUtilsParserManager.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/YangUtilsParserManager.java
@@ -31,7 +31,7 @@
 import org.onosproject.yangutils.parser.impl.parserutils.ParseTreeErrorListener;
 
 /**
- * Manages file parsing, parse tree creation and data model tree creation
+ * Represents file parsing, parse tree creation and data model tree creation
  * corresponding to an input YANG file.
  */
 public class YangUtilsParserManager implements YangUtilsParser {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BaseFileListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BaseFileListener.java
index b590f57..7b41b77 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BaseFileListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BaseFileListener.java
@@ -22,6 +22,7 @@
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
@@ -41,7 +42,7 @@
  */
 
 /**
- * Implements call back function corresponding to the "base rule" defined in
+ * Representation of call back function corresponding to the "base rule" defined in
  * ANTLR grammar file.
  */
 public final class BaseFileListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BelongsToListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BelongsToListener.java
index cf840ef..ff25f00 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BelongsToListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BelongsToListener.java
@@ -57,7 +57,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the
+ * Represents listener based call back function corresponding to the
  * "belongs to" rule defined in ANTLR grammar file for corresponding ABNF rule
  * in RFC 6020.
  */
@@ -116,16 +116,16 @@
 
             Parsable tmpNode = listener.getParsedDataStack().peek();
             switch (tmpNode.getYangConstructType()) {
-            case SUB_MODULE_DATA: {
-                YangSubModule subModule = (YangSubModule) tmpNode;
-                subModule.setBelongsTo((YangBelongsTo) tmpBelongstoNode);
-                subModule.setPrefix(subModule.getBelongsTo().getPrefix());
-                break;
-            }
-            default:
-                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, BELONGS_TO_DATA,
-                                                                        ctx.identifier().getText(),
-                                                                        EXIT));
+                case SUB_MODULE_DATA: {
+                    YangSubModule subModule = (YangSubModule) tmpNode;
+                    subModule.setBelongsTo((YangBelongsTo) tmpBelongstoNode);
+                    subModule.setPrefix(subModule.getBelongsTo().getPrefix());
+                    break;
+                }
+                default:
+                    throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, BELONGS_TO_DATA,
+                            ctx.identifier().getText(),
+                            EXIT));
             }
         } else {
             throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, BELONGS_TO_DATA,
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BitListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BitListener.java
index 7f0a3c3..ddd08f3 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BitListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BitListener.java
@@ -82,7 +82,7 @@
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 
 /**
- * Implements listener based call back function corresponding to the "bit"
+ * Represents listener based call back function corresponding to the "bit"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class BitListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BitsListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BitsListener.java
index cc816d1..0501806 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BitsListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BitsListener.java
@@ -61,7 +61,7 @@
 import static org.onosproject.yangutils.utils.YangConstructType.TYPE_DATA;
 
 /**
- * Implements listener based call back function corresponding to the "bits" rule
+ * Represents listener based call back function corresponding to the "bits" rule
  * defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class BitsListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/CaseListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/CaseListener.java
index b059c46..d91bf25 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/CaseListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/CaseListener.java
@@ -67,7 +67,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "case" rule
+ * Represents listener based call back function corresponding to the "case" rule
  * defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class CaseListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ChoiceListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ChoiceListener.java
index a7cadc6..ac14a1c 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ChoiceListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ChoiceListener.java
@@ -86,7 +86,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "choice"
+ * Represents listener based call back function corresponding to the "choice"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ChoiceListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
index 792f1cc..b8ab6a1 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ConfigListener.java
@@ -49,7 +49,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "config"
+ * Represents listener based call back function corresponding to the "config"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ConfigListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ContactListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ContactListener.java
index 933ccc9..069708d 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ContactListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ContactListener.java
@@ -23,12 +23,12 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.utils.YangConstructType.CONTACT_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.CONTACT_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -71,7 +71,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "contact"
+ * Represents listener based call back function corresponding to the "contact"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ContactListener {
@@ -97,19 +97,19 @@
         // Obtain the node of the stack.
         Parsable tmpNode = listener.getParsedDataStack().peek();
         switch (tmpNode.getYangConstructType()) {
-        case MODULE_DATA: {
-            YangModule module = (YangModule) tmpNode;
-            module.setContact(ctx.string().getText());
-            break;
-        }
-        case SUB_MODULE_DATA: {
-            YangSubModule subModule = (YangSubModule) tmpNode;
-            subModule.setContact(ctx.string().getText());
-            break;
-        }
-        default:
-            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, CONTACT_DATA,
-                                                                    ctx.string().getText(), ENTRY));
+            case MODULE_DATA: {
+                YangModule module = (YangModule) tmpNode;
+                module.setContact(ctx.string().getText());
+                break;
+            }
+            case SUB_MODULE_DATA: {
+                YangSubModule subModule = (YangSubModule) tmpNode;
+                subModule.setContact(ctx.string().getText());
+                break;
+            }
+            default:
+                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, CONTACT_DATA,
+                        ctx.string().getText(), ENTRY));
         }
     }
 }
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ContainerListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ContainerListener.java
index 0a12685..f7dbf8c 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ContainerListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ContainerListener.java
@@ -16,15 +16,15 @@
 
 package org.onosproject.yangutils.parser.impl.listeners;
 
+import org.onosproject.yangutils.datamodel.YangAugment;
 import org.onosproject.yangutils.datamodel.YangCase;
 import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangInput;
 import org.onosproject.yangutils.datamodel.YangList;
 import org.onosproject.yangutils.datamodel.YangModule;
 import org.onosproject.yangutils.datamodel.YangNode;
 import org.onosproject.yangutils.datamodel.YangNotification;
-import org.onosproject.yangutils.datamodel.YangInput;
 import org.onosproject.yangutils.datamodel.YangOutput;
-import org.onosproject.yangutils.datamodel.YangAugment;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
@@ -83,7 +83,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "container"
+ * Represents listener based call back function corresponding to the "container"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ContainerListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListener.java
index ed7c6f3..fc9b84a 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListener.java
@@ -45,7 +45,6 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
@@ -54,7 +53,7 @@
 import static org.onosproject.yangutils.utils.YangConstructType.DEFAULT_DATA;
 
 /**
- * Listener implementation for default YANG statement.
+ * Represents listener for default YANG statement.
  */
 public final class DefaultListener {
 
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DescriptionListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DescriptionListener.java
index b735b79..32bd3aa 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DescriptionListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DescriptionListener.java
@@ -22,12 +22,12 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.utils.YangConstructType.DESCRIPTION_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.DESCRIPTION_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -40,7 +40,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "description"
+ * Represents listener based call back function corresponding to the "description"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class DescriptionListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumListener.java
index 4948666..103a7ee 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumListener.java
@@ -64,10 +64,10 @@
 import org.onosproject.yangutils.datamodel.YangEnumeration;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.Parsable;
-import static org.onosproject.yangutils.utils.YangConstructType.ENUM_DATA;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
@@ -77,9 +77,10 @@
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.ENUM_DATA;
 
 /**
- * Implements listener based call back function corresponding to the "enum" rule
+ * Represents listener based call back function corresponding to the "enum" rule
  * defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class EnumListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumerationListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumerationListener.java
index 2ce05c4..9bca04d 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumerationListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/EnumerationListener.java
@@ -62,7 +62,7 @@
 import static org.onosproject.yangutils.utils.YangConstructType.TYPE_DATA;
 
 /**
- * Implements listener based call back function corresponding to the
+ * Represents listener based call back function corresponding to the
  * "enumeration" rule defined in ANTLR grammar file for corresponding ABNF rule
  * in RFC 6020.
  */
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/GroupingListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/GroupingListener.java
index 707dfeb..c81e554 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/GroupingListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/GroupingListener.java
@@ -53,7 +53,6 @@
 import static org.onosproject.yangutils.utils.YangConstructType.STATUS_DATA;
 import static org.onosproject.yangutils.utils.YangConstructType.TYPEDEF_DATA;
 
-
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
  *
@@ -77,7 +76,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "grouping"
+ * Represents listener based call back function corresponding to the "grouping"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class GroupingListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ImportListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ImportListener.java
index 15e7805..03938b1 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ImportListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ImportListener.java
@@ -24,13 +24,13 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.utils.YangConstructType.IMPORT_DATA;
 
@@ -57,7 +57,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "import"
+ * Represents listener based call back function corresponding to the "import"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ImportListener {
@@ -111,20 +111,20 @@
 
             Parsable tmpNode = listener.getParsedDataStack().peek();
             switch (tmpNode.getYangConstructType()) {
-            case MODULE_DATA: {
-                YangModule module = (YangModule) tmpNode;
-                module.addToImportList((YangImport) tmpImportNode);
-                break;
-            }
-            case SUB_MODULE_DATA: {
-                YangSubModule subModule = (YangSubModule) tmpNode;
-                subModule.addToImportList((YangImport) tmpImportNode);
-                break;
-            }
-            default:
-                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, IMPORT_DATA,
-                                                                        ctx.identifier().getText(),
-                                                                        EXIT));
+                case MODULE_DATA: {
+                    YangModule module = (YangModule) tmpNode;
+                    module.addToImportList((YangImport) tmpImportNode);
+                    break;
+                }
+                case SUB_MODULE_DATA: {
+                    YangSubModule subModule = (YangSubModule) tmpNode;
+                    subModule.addToImportList((YangImport) tmpImportNode);
+                    break;
+                }
+                default:
+                    throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, IMPORT_DATA,
+                            ctx.identifier().getText(),
+                            EXIT));
             }
         } else {
             throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, IMPORT_DATA,
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/IncludeListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/IncludeListener.java
index 0d9f7cc..721b9fe 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/IncludeListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/IncludeListener.java
@@ -56,7 +56,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "include"
+ * Represents listener based call back function corresponding to the "include"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class IncludeListener {
@@ -110,20 +110,20 @@
 
             Parsable tmpNode = listener.getParsedDataStack().peek();
             switch (tmpNode.getYangConstructType()) {
-            case MODULE_DATA: {
-                YangModule module = (YangModule) tmpNode;
-                module.addToIncludeList((YangInclude) tmpIncludeNode);
-                break;
-            }
-            case SUB_MODULE_DATA: {
-                YangSubModule subModule = (YangSubModule) tmpNode;
-                subModule.addToIncludeList((YangInclude) tmpIncludeNode);
-                break;
-            }
-            default:
-                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, INCLUDE_DATA,
-                                                                        ctx.identifier().getText(),
-                                                                        EXIT));
+                case MODULE_DATA: {
+                    YangModule module = (YangModule) tmpNode;
+                    module.addToIncludeList((YangInclude) tmpIncludeNode);
+                    break;
+                }
+                case SUB_MODULE_DATA: {
+                    YangSubModule subModule = (YangSubModule) tmpNode;
+                    subModule.addToIncludeList((YangInclude) tmpIncludeNode);
+                    break;
+                }
+                default:
+                    throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, INCLUDE_DATA,
+                            ctx.identifier().getText(),
+                            EXIT));
             }
         } else {
             throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, INCLUDE_DATA,
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/InputListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/InputListener.java
index b4ce827..66233fc 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/InputListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/InputListener.java
@@ -60,7 +60,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "input"
+ * Represents listener based call back function corresponding to the "input"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class InputListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/KeyListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/KeyListener.java
index a3ce22c..81223fd 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/KeyListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/KeyListener.java
@@ -23,15 +23,15 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.utils.YangConstructType.KEY_DATA;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.KEY_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -45,7 +45,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "key"
+ * Represesnts listener based call back function corresponding to the "key"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class KeyListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafListListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafListListener.java
index 675c4ab..6b5afe3 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafListListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafListListener.java
@@ -23,7 +23,6 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerCollisionDetector.detectCollidingChildUtil;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
@@ -31,6 +30,7 @@
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateCardinalityEqualsOne;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateCardinalityMaxOne;
@@ -72,7 +72,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "leaf-list"
+ * Represents listener based call back function corresponding to the "leaf-list"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class LeafListListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafListener.java
index 3927236..738ffa9 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/LeafListener.java
@@ -27,7 +27,6 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerCollisionDetector.detectCollidingChildUtil;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
@@ -35,6 +34,7 @@
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateCardinalityEqualsOne;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateCardinalityMaxOne;
@@ -74,7 +74,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "leaf" rule
+ * Represents listener based call back function corresponding to the "leaf" rule
  * defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class LeafListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ListListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ListListener.java
index 6d3036e..a6c5496 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ListListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ListListener.java
@@ -16,15 +16,15 @@
 
 package org.onosproject.yangutils.parser.impl.listeners;
 
+import org.onosproject.yangutils.datamodel.YangAugment;
 import org.onosproject.yangutils.datamodel.YangCase;
 import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangInput;
 import org.onosproject.yangutils.datamodel.YangList;
 import org.onosproject.yangutils.datamodel.YangModule;
 import org.onosproject.yangutils.datamodel.YangNode;
 import org.onosproject.yangutils.datamodel.YangNotification;
-import org.onosproject.yangutils.datamodel.YangInput;
 import org.onosproject.yangutils.datamodel.YangOutput;
-import org.onosproject.yangutils.datamodel.YangAugment;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
@@ -89,7 +89,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "list" rule
+ * Represents listener based call back function corresponding to the "list" rule
  * defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ListListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MandatoryListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MandatoryListener.java
index 610cb66..1363091 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MandatoryListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MandatoryListener.java
@@ -22,13 +22,13 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidBooleanValue;
-import static org.onosproject.yangutils.utils.YangConstructType.MANDATORY_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidBooleanValue;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.MANDATORY_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -48,7 +48,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "mandatory"
+ * Represents listener based call back function corresponding to the "mandatory"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class MandatoryListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MaxElementsListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MaxElementsListener.java
index ea8e83d..efec3d1 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MaxElementsListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MaxElementsListener.java
@@ -47,7 +47,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the
+ * Represents listener based call back function corresponding to the
  * "max-elements" rule defined in ANTLR grammar file for corresponding ABNF rule
  * in RFC 6020.
  */
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListener.java
index 634862b..c037106 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/MinElementsListener.java
@@ -23,13 +23,13 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidNonNegativeIntegerValue;
-import static org.onosproject.yangutils.utils.YangConstructType.MIN_ELEMENT_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidNonNegativeIntegerValue;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.MIN_ELEMENT_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -47,7 +47,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "min-elements"
+ * Represents listener based call back function corresponding to the "min-elements"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class MinElementsListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
index 44332cb..2cb6187 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ModuleListener.java
@@ -57,7 +57,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "module"
+ * Represents listener based call back function corresponding to the "module"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ModuleListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListener.java
index 1c018da..8278137 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NamespaceListener.java
@@ -55,7 +55,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "namespace"
+ * Represents listener based call back function corresponding to the "namespace"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class NamespaceListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListener.java
index 729422c..58daefb 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/NotificationListener.java
@@ -16,10 +16,10 @@
 
 package org.onosproject.yangutils.parser.impl.listeners;
 
-import org.onosproject.yangutils.datamodel.YangNotification;
 import org.onosproject.yangutils.datamodel.YangModule;
-import org.onosproject.yangutils.datamodel.YangSubModule;
 import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNotification;
+import org.onosproject.yangutils.datamodel.YangSubModule;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
@@ -33,17 +33,20 @@
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructExtendedListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.*;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.UNHANDLED_PARSED_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateCardinalityMaxOne;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.validateMutuallyExclusiveChilds;
-import static org.onosproject.yangutils.utils.YangConstructType.NOTIFICATION_DATA;
-import static org.onosproject.yangutils.utils.YangConstructType.STATUS_DATA;
 import static org.onosproject.yangutils.utils.YangConstructType.DESCRIPTION_DATA;
-import static org.onosproject.yangutils.utils.YangConstructType.REFERENCE_DATA;
-import static org.onosproject.yangutils.utils.YangConstructType.TYPEDEF_DATA;
 import static org.onosproject.yangutils.utils.YangConstructType.GROUPING_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.NOTIFICATION_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.REFERENCE_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.STATUS_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.TYPEDEF_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -70,7 +73,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "notification"
+ * Represents listener based call back function corresponding to the "notification"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class NotificationListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/OrganizationListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/OrganizationListener.java
index 99d6157..19a1e64 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/OrganizationListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/OrganizationListener.java
@@ -23,12 +23,12 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.utils.YangConstructType.ORGANIZATION_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.ORGANIZATION_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -72,7 +72,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the
+ * Represents listener based call back function corresponding to the
  * "organization" rule defined in ANTLR grammar file for corresponding ABNF rule
  * in RFC 6020.
  */
@@ -101,19 +101,19 @@
         // Obtain the node of the stack.
         Parsable tmpNode = listener.getParsedDataStack().peek();
         switch (tmpNode.getYangConstructType()) {
-        case MODULE_DATA: {
-            YangModule module = (YangModule) tmpNode;
-            module.setOrganization(ctx.string().getText());
-            break;
-        }
-        case SUB_MODULE_DATA: {
-            YangSubModule subModule = (YangSubModule) tmpNode;
-            subModule.setOrganization(ctx.string().getText());
-            break;
-        }
-        default:
-            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, ORGANIZATION_DATA,
-                                                                    ctx.string().getText(), ENTRY));
+            case MODULE_DATA: {
+                YangModule module = (YangModule) tmpNode;
+                module.setOrganization(ctx.string().getText());
+                break;
+            }
+            case SUB_MODULE_DATA: {
+                YangSubModule subModule = (YangSubModule) tmpNode;
+                subModule.setOrganization(ctx.string().getText());
+                break;
+            }
+            default:
+                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, ORGANIZATION_DATA,
+                        ctx.string().getText(), ENTRY));
         }
     }
 }
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/OutputListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/OutputListener.java
index 069a09a..f0df739 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/OutputListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/OutputListener.java
@@ -57,7 +57,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "output"
+ * Represents listener based call back function corresponding to the "output"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class OutputListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PositionListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PositionListener.java
index d754cb3..92c08ca 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PositionListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PositionListener.java
@@ -50,7 +50,7 @@
 import static org.onosproject.yangutils.utils.YangConstructType.POSITION_DATA;
 
 /**
- * Implements listener based call back function corresponding to the "position"
+ * Represents listener based call back function corresponding to the "position"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class PositionListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PrefixListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PrefixListener.java
index 4a8f20a..90e278b 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PrefixListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PrefixListener.java
@@ -24,13 +24,13 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
-import static org.onosproject.yangutils.utils.YangConstructType.PREFIX_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.getValidIdentifier;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.PREFIX_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -56,7 +56,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "prefix"
+ * Represents listener based call back function corresponding to the "prefix"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class PrefixListener {
@@ -84,24 +84,24 @@
         // Obtain the node of the stack.
         Parsable tmpNode = listener.getParsedDataStack().peek();
         switch (tmpNode.getYangConstructType()) {
-        case MODULE_DATA: {
-            YangModule module = (YangModule) tmpNode;
-            module.setPrefix(identifier);
-            break;
-        }
-        case IMPORT_DATA: {
-            YangImport importNode = (YangImport) tmpNode;
-            importNode.setPrefixId(identifier);
-            break;
-        }
-        case BELONGS_TO_DATA: {
-            YangBelongsTo belongstoNode = (YangBelongsTo) tmpNode;
-            belongstoNode.setPrefix(identifier);
-            break;
-        }
-        default:
-            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, PREFIX_DATA,
-                                                                    ctx.identifier().getText(), ENTRY));
+            case MODULE_DATA: {
+                YangModule module = (YangModule) tmpNode;
+                module.setPrefix(identifier);
+                break;
+            }
+            case IMPORT_DATA: {
+                YangImport importNode = (YangImport) tmpNode;
+                importNode.setPrefixId(identifier);
+                break;
+            }
+            case BELONGS_TO_DATA: {
+                YangBelongsTo belongstoNode = (YangBelongsTo) tmpNode;
+                belongstoNode.setPrefix(identifier);
+                break;
+            }
+            default:
+                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, PREFIX_DATA,
+                        ctx.identifier().getText(), ENTRY));
         }
     }
 }
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PresenceListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PresenceListener.java
index e0c272b..45b411b 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PresenceListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/PresenceListener.java
@@ -22,13 +22,13 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.utils.YangConstructType.PRESENCE_DATA;
-import static org.onosproject.yangutils.utils.YangConstructType.CONTAINER_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.CONTAINER_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.PRESENCE_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -41,7 +41,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "presence"
+ * Represents listener based call back function corresponding to the "presence"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class PresenceListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListener.java
index 6563178..dfb9458 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RangeRestrictionListener.java
@@ -59,7 +59,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "range"
+ * Represents listener based call back function corresponding to the "range"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class RangeRestrictionListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ReferenceListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ReferenceListener.java
index e8421bd..a90ab3c 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ReferenceListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ReferenceListener.java
@@ -22,12 +22,12 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.utils.YangConstructType.REFERENCE_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.REFERENCE_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -40,7 +40,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "reference"
+ * Represents listener based call back function corresponding to the "reference"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ReferenceListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListener.java
index ca1d588..72c5987 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListener.java
@@ -23,12 +23,12 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.isDateValid;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.isDateValid;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 import static org.onosproject.yangutils.utils.YangConstructType.REVISION_DATE_DATA;
 
@@ -61,7 +61,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the
+ * Represents listener based call back function corresponding to the
  * "revision date" rule defined in ANTLR grammar file for corresponding ABNF
  * rule in RFC 6020.
  */
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionListener.java
index 27515c0..6573a43 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionListener.java
@@ -24,16 +24,16 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.isDateValid;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
-import static org.onosproject.yangutils.utils.YangConstructType.REVISION_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.isDateValid;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.REVISION_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -64,7 +64,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "revision"
+ * Represents listener based call back function corresponding to the "revision"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class RevisionListener {
@@ -132,20 +132,20 @@
 
             Parsable tmpNode = listener.getParsedDataStack().peek();
             switch (tmpNode.getYangConstructType()) {
-            case MODULE_DATA: {
-                YangModule module = (YangModule) tmpNode;
-                module.setRevision((YangRevision) tmpRevisionNode);
-                break;
-            }
-            case SUB_MODULE_DATA: {
-                YangSubModule subModule = (YangSubModule) tmpNode;
-                subModule.setRevision((YangRevision) tmpRevisionNode);
-                break;
-            }
-            default:
-                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, REVISION_DATA,
-                                                                        ctx.dateArgumentString().getText(),
-                                                                        EXIT));
+                case MODULE_DATA: {
+                    YangModule module = (YangModule) tmpNode;
+                    module.setRevision((YangRevision) tmpRevisionNode);
+                    break;
+                }
+                case SUB_MODULE_DATA: {
+                    YangSubModule subModule = (YangSubModule) tmpNode;
+                    subModule.setRevision((YangRevision) tmpRevisionNode);
+                    break;
+                }
+                default:
+                    throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, REVISION_DATA,
+                            ctx.dateArgumentString().getText(),
+                            EXIT));
             }
         } else {
             throw new ParserException(constructListenerErrorMessage(MISSING_CURRENT_HOLDER, REVISION_DATA,
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RpcListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RpcListener.java
index e72323b..ae9e04c 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RpcListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RpcListener.java
@@ -72,7 +72,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "rpc"
+ * Represents listener based call back function corresponding to the "rpc"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class RpcListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ShortCaseListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ShortCaseListener.java
index 6d2bd82..7744866 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ShortCaseListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ShortCaseListener.java
@@ -57,7 +57,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "short
+ * Represents listener based call back function corresponding to the "short
  * case" rule defined in ANTLR grammar file for corresponding ABNF rule in RFC
  * 6020.
  */
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/StatusListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/StatusListener.java
index 0a3e3e5..b91003b 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/StatusListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/StatusListener.java
@@ -23,14 +23,14 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
-import static org.onosproject.yangutils.utils.YangConstructType.STATUS_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_CONTENT;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerUtil.removeQuotesAndHandleConcat;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.STATUS_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -48,7 +48,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "status"
+ * Represents listener based call back function corresponding to the "status"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class StatusListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/SubModuleListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/SubModuleListener.java
index bcece84..d20f90a 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/SubModuleListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/SubModuleListener.java
@@ -58,7 +58,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "submodule"
+ * Represents listener based call back function corresponding to the "submodule"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class SubModuleListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeDefListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeDefListener.java
index 8b9d772..bfa22a4 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeDefListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeDefListener.java
@@ -87,7 +87,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "typedef"
+ * Represents listener based call back function corresponding to the "typedef"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class TypeDefListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeListener.java
index fee102f..c953be5 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/TypeListener.java
@@ -62,7 +62,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "type" rule
+ * Represents listener based call back function corresponding to the "type" rule
  * defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class TypeListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnionListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnionListener.java
index fa94f80..79ce0b9 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnionListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnionListener.java
@@ -60,10 +60,11 @@
 import static org.onosproject.yangutils.utils.YangConstructType.UNION_DATA;
 
 /**
- * Implements listener based call back function corresponding to the "union" rule
+ * Represents listener based call back function corresponding to the "union" rule
  * defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class UnionListener {
+
     /**
      * Creates a new union listener.
      */
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListener.java
index bc99843..c284fc2 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListener.java
@@ -23,12 +23,12 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.utils.YangConstructType.UNITS_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.UNITS_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -41,7 +41,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "units"
+ * Represents listener based call back function corresponding to the "units"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class UnitsListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java
index d537fb8..4e2925a 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/UsesListener.java
@@ -90,7 +90,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "uses"
+ * Represents listener based call back function corresponding to the "uses"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class UsesListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ValueListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ValueListener.java
index ec5482d..92a0d42 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ValueListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/ValueListener.java
@@ -29,18 +29,19 @@
 import org.onosproject.yangutils.datamodel.YangEnum;
 import org.onosproject.yangutils.datamodel.YangEnumeration;
 import org.onosproject.yangutils.parser.Parsable;
-import static org.onosproject.yangutils.utils.YangConstructType.VALUE_DATA;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
+import static org.onosproject.yangutils.utils.YangConstructType.VALUE_DATA;
 
 /**
- * Implements listener based call back function corresponding to the "value"
+ * Represents listener based call back function corresponding to the "value"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class ValueListener {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/VersionListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/VersionListener.java
index 35b2917..62dfb70 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/VersionListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/VersionListener.java
@@ -65,7 +65,7 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "version"
+ * Represents listener based call back function corresponding to the "version"
  * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
  */
 public final class VersionListener {
@@ -94,19 +94,19 @@
         // Obtain the node of the stack.
         Parsable tmpNode = listener.getParsedDataStack().peek();
         switch (tmpNode.getYangConstructType()) {
-        case MODULE_DATA: {
-            YangModule module = (YangModule) tmpNode;
-            module.setVersion(version);
-            break;
-        }
-        case SUB_MODULE_DATA: {
-            YangSubModule subModule = (YangSubModule) tmpNode;
-            subModule.setVersion(version);
-            break;
-        }
-        default:
-            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, VERSION_DATA,
-                                                                    ctx.version().getText(), ENTRY));
+            case MODULE_DATA: {
+                YangModule module = (YangModule) tmpNode;
+                module.setVersion(version);
+                break;
+            }
+            case SUB_MODULE_DATA: {
+                YangSubModule subModule = (YangSubModule) tmpNode;
+                subModule.setVersion(version);
+                break;
+            }
+            default:
+                throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, VERSION_DATA,
+                        ctx.version().getText(), ENTRY));
         }
     }
 }
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerCollisionDetector.java b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerCollisionDetector.java
index 1e2d225..98b3429 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerCollisionDetector.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerCollisionDetector.java
@@ -20,13 +20,14 @@
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
+import org.onosproject.yangutils.utils.YangConstructType;
+
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
-import org.onosproject.yangutils.utils.YangConstructType;
 
 /**
- * Check the YANG construct collision in a YANG file.
+ * Represents the detector of YANG construct collision in a YANG file.
  */
 public final class ListenerCollisionDetector {
 
@@ -52,7 +53,7 @@
      */
     public static void detectCollidingChildUtil(TreeWalkListener listener, int line, int charPosition,
             String identifierName, YangConstructType constructType)
-                    throws ParserException {
+            throws ParserException {
 
         if (listener.getParsedDataStack().peek() instanceof CollisionDetector) {
             try {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorLocation.java b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorLocation.java
index 1c29fa6..c1c2888 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorLocation.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorLocation.java
@@ -17,7 +17,7 @@
 package org.onosproject.yangutils.parser.impl.parserutils;
 
 /**
- * Maintains listener error location.
+ * Represents listener error location.
  */
 public enum ListenerErrorLocation {
     /**
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorMessageConstruction.java b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorMessageConstruction.java
index 7064e3b..141e3dc 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorMessageConstruction.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorMessageConstruction.java
@@ -18,17 +18,17 @@
 
 import org.onosproject.yangutils.utils.YangConstructType;
 
-import static org.onosproject.yangutils.utils.YangConstructType.getYangConstructType;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.getErrorLocationMessage;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.getErrorType;
+import static org.onosproject.yangutils.utils.YangConstructType.getYangConstructType;
 
 /**
- * It's a utility to help construct detailed error message.
+ * Represents a utility to help construct detailed error message.
  */
 public final class ListenerErrorMessageConstruction {
 
     /**
-     * Private constructor.
+     * Creates a object of listen error message.
      */
     private ListenerErrorMessageConstruction() {
     }
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorType.java b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorType.java
index 6b520d9..f1cb284 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorType.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerErrorType.java
@@ -17,7 +17,7 @@
 package org.onosproject.yangutils.parser.impl.parserutils;
 
 /**
- * Maintains listener error type.
+ * Represents listener error type.
  */
 public enum ListenerErrorType {
     /**
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerUtil.java b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerUtil.java
index fd81898..ffb50e9 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerUtil.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerUtil.java
@@ -26,13 +26,14 @@
 import org.antlr.v4.runtime.ParserRuleContext;
 import org.onosproject.yangutils.datamodel.YangNodeIdentifier;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
-import org.onosproject.yangutils.utils.YangConstructType;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.utils.YangConstructType;
 
 /**
- * It's a utility for listener.
+ * Represents an utility for listener.
  */
 public final class ListenerUtil {
+
     private static final Pattern IDENTIFIER_PATTERN = Pattern.compile("[a-zA-Z_][a-zA-Z0-9_.-]*");
     private static final String NON_NEGATIVE_INTEGER_PATTERN = "[0-9]+";
     private static final String PLUS = "+";
@@ -154,7 +155,7 @@
      * @return valid non negative integer value
      */
     public static int getValidNonNegativeIntegerValue(String integerValue, YangConstructType yangConstruct,
-                                           ParserRuleContext ctx) {
+            ParserRuleContext ctx) {
 
         String value = removeQuotesAndHandleConcat(integerValue);
         if (!value.matches(NON_NEGATIVE_INTEGER_PATTERN)) {
@@ -178,7 +179,7 @@
      * @return boolean value either true or false
      */
     public static boolean getValidBooleanValue(String booleanValue, YangConstructType yangConstruct,
-                                                ParserRuleContext ctx) {
+            ParserRuleContext ctx) {
 
         String value = removeQuotesAndHandleConcat(booleanValue);
         if (value.equals(TRUE_KEYWORD)) {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerValidation.java b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerValidation.java
index 26d3088..f2c0e7c 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerValidation.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerValidation.java
@@ -16,6 +16,9 @@
 
 package org.onosproject.yangutils.parser.impl.parserutils;
 
+import java.util.Iterator;
+import java.util.List;
+
 import org.antlr.v4.runtime.ParserRuleContext;
 import org.onosproject.yangutils.datamodel.YangContainer;
 import org.onosproject.yangutils.datamodel.YangList;
@@ -23,15 +26,13 @@
 import org.onosproject.yangutils.parser.Parsable;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import org.onosproject.yangutils.utils.YangConstructType;
+
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
 import static org.onosproject.yangutils.utils.YangConstructType.getYangConstructType;
 
-import java.util.Iterator;
-import java.util.List;
-
 /**
- * It's a utility to carry out listener validation.
+ * Represents a utility to carry out listener validation.
  */
 public final class ListenerValidation {
 
@@ -54,6 +55,7 @@
     public static void checkStackIsNotEmpty(TreeWalkListener listener, ListenerErrorType errorType,
             YangConstructType yangConstructType, String parsableDataTypeName,
             ListenerErrorLocation errorLocation) {
+
         if (listener.getParsedDataStack().empty()) {
             /*
              * If stack is empty it indicates error condition, value of
@@ -100,6 +102,7 @@
      * @return true/false parent's config value
      */
     public static boolean getParentNodeConfig(TreeWalkListener listener) {
+
         YangNode parentNode;
         Parsable curData = listener.getParsedDataStack().peek();
         if (curData instanceof YangNode) {
@@ -125,7 +128,7 @@
      * @throws ParserException exception if cardinality check fails
      */
     public static void validateCardinalityMaxOne(List<?> childContext, YangConstructType yangChildConstruct,
-                                                 YangConstructType yangParentConstruct, String parentName)
+            YangConstructType yangParentConstruct, String parentName)
             throws ParserException {
 
         if (!childContext.isEmpty() && childContext.size() != 1) {
@@ -152,8 +155,8 @@
      * @throws ParserException exception if cardinality check fails
      */
     public static void validateCardinalityEqualsOne(List<?> childContext, YangConstructType yangChildConstruct,
-                                                    YangConstructType yangParentConstruct, String parentName,
-                                                    ParserRuleContext parentContext)
+            YangConstructType yangParentConstruct, String parentName,
+            ParserRuleContext parentContext)
             throws ParserException {
 
         if (childContext.isEmpty()) {
@@ -187,8 +190,8 @@
      * @throws ParserException exception if cardinality check fails
      */
     public static void validateCardinalityNonZero(List<?> childContext, YangConstructType yangChildConstruct,
-                                                  YangConstructType yangParentConstruct, String parentName,
-                                                  ParserRuleContext parentContext)
+            YangConstructType yangParentConstruct, String parentName,
+            ParserRuleContext parentContext)
             throws ParserException {
 
         if (childContext.isEmpty()) {
@@ -216,8 +219,8 @@
      * @throws ParserException exception if cardinality check fails
      */
     public static void validateMutuallyExclusiveChilds(List<?> child1Context, YangConstructType yangChild1Construct,
-                                                       List<?> child2Context, YangConstructType yangChild2Construct,
-                                                       YangConstructType yangParentConstruct, String parentName)
+            List<?> child2Context, YangConstructType yangChild2Construct,
+            YangConstructType yangParentConstruct, String parentName)
             throws ParserException {
 
         if (!child1Context.isEmpty() && !child2Context.isEmpty()) {
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ParseTreeErrorListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ParseTreeErrorListener.java
index 89afb78..af81d6f 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ParseTreeErrorListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ParseTreeErrorListener.java
@@ -22,6 +22,7 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 
 /**
+ * Represent the parse tree error listener.
  * By default, ANTLR sends all errors to standard error, this is changed by
  * providing this new implementation of interface ANTLRErrorListener. The
  * interface has a syntaxError() method that applies to both lexer and parser.