diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java
new file mode 100644
index 0000000..6cb764b
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/TreeWalkListener.java
@@ -0,0 +1,1170 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl;
+
+import org.antlr.v4.runtime.ParserRuleContext;
+import org.antlr.v4.runtime.tree.ErrorNode;
+import org.antlr.v4.runtime.tree.TerminalNode;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.parser.Parsable;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangListener;
+import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
+import org.onosproject.yangutils.parser.impl.parserutils.ListenerError;
+
+import java.util.Stack;
+
+/**
+ * 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.
+ */
+public class TreeWalkListener implements GeneratedYangListener {
+
+    // List of parsable node entries maintained in stack
+    private Stack<Parsable> parsedDataStack = new Stack<>();
+
+    // Parse tree root node
+    private YangNode rootNode;
+
+    // Maintains the state of Exception.
+    private ListenerError errorInformation = new ListenerError();
+
+    /**
+     * Returns stack of parsable data.
+     *
+     * @return stack of parsable data
+     */
+    public Stack<Parsable> getParsedDataStack() {
+        return parsedDataStack;
+    }
+
+    /**
+     * Returns error information.
+     *
+     * @return error information object having exception flag and message
+     */
+    public ListenerError getErrorInformation() {
+        return errorInformation;
+    }
+
+    /**
+     * Returns root node.
+     *
+     * @return rootNode of data model tree.
+     */
+    public YangNode getRootNode() {
+        return rootNode;
+    }
+
+    /**
+     * Set parsed data stack.
+     *
+     * @param parsedDataStack stack of parsable data objects.
+     */
+    public void setParsedDataStack(Stack<Parsable> parsedDataStack) {
+        this.parsedDataStack = parsedDataStack;
+    }
+
+    /**
+     * Set root node.
+     *
+     * @param rootNode root node of data model tree.
+     */
+    public void setRootNode(YangNode rootNode) {
+        this.rootNode = rootNode;
+    }
+
+    /**
+     * Set listener error information.
+     *
+     * @param errorInformation error occurred during tree walk.
+     */
+    public void setErrorInformation(ListenerError errorInformation) {
+        this.errorInformation = errorInformation;
+    }
+
+    @Override
+    public void enterYangfile(GeneratedYangParser.YangfileContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitYangfile(GeneratedYangParser.YangfileContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterModuleStatement(GeneratedYangParser.ModuleStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitModuleStatement(GeneratedYangParser.ModuleStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterModuleBody(GeneratedYangParser.ModuleBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitModuleBody(GeneratedYangParser.ModuleBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterModuleHeaderStatement(GeneratedYangParser.ModuleHeaderStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitModuleHeaderStatement(GeneratedYangParser.ModuleHeaderStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterLinkageStatements(GeneratedYangParser.LinkageStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitLinkageStatements(GeneratedYangParser.LinkageStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterMetaStatements(GeneratedYangParser.MetaStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitMetaStatements(GeneratedYangParser.MetaStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRevisionStatements(GeneratedYangParser.RevisionStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRevisionStatements(GeneratedYangParser.RevisionStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterBodyStatements(GeneratedYangParser.BodyStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitBodyStatements(GeneratedYangParser.BodyStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterYangVersionStatement(GeneratedYangParser.YangVersionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitYangVersionStatement(GeneratedYangParser.YangVersionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterNamespaceStatement(GeneratedYangParser.NamespaceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitNamespaceStatement(GeneratedYangParser.NamespaceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterPrefixStatement(GeneratedYangParser.PrefixStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitPrefixStatement(GeneratedYangParser.PrefixStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterImportStatement(GeneratedYangParser.ImportStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitImportStatement(GeneratedYangParser.ImportStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterImportStatementBody(GeneratedYangParser.ImportStatementBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitImportStatementBody(GeneratedYangParser.ImportStatementBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRevisionDateStatement(GeneratedYangParser.RevisionDateStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRevisionDateStatement(GeneratedYangParser.RevisionDateStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterIncludeStatement(GeneratedYangParser.IncludeStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitIncludeStatement(GeneratedYangParser.IncludeStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterOrganizationStatement(GeneratedYangParser.OrganizationStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitOrganizationStatement(GeneratedYangParser.OrganizationStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterContactStatement(GeneratedYangParser.ContactStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitContactStatement(GeneratedYangParser.ContactStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterDescriptionStatement(GeneratedYangParser.DescriptionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitDescriptionStatement(GeneratedYangParser.DescriptionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterReferenceStatement(GeneratedYangParser.ReferenceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitReferenceStatement(GeneratedYangParser.ReferenceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRevisionStatement(GeneratedYangParser.RevisionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRevisionStatement(GeneratedYangParser.RevisionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRevisionStatementBody(GeneratedYangParser.RevisionStatementBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRevisionStatementBody(GeneratedYangParser.RevisionStatementBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterSubModuleStatement(GeneratedYangParser.SubModuleStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitSubModuleStatement(GeneratedYangParser.SubModuleStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterSubmoduleBody(GeneratedYangParser.SubmoduleBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitSubmoduleBody(GeneratedYangParser.SubmoduleBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterSubmoduleHeaderStatement(GeneratedYangParser.SubmoduleHeaderStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitSubmoduleHeaderStatement(GeneratedYangParser.SubmoduleHeaderStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterBelongstoStatement(GeneratedYangParser.BelongstoStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitBelongstoStatement(GeneratedYangParser.BelongstoStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterBelongstoStatementBody(GeneratedYangParser.BelongstoStatementBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitBelongstoStatementBody(GeneratedYangParser.BelongstoStatementBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterExtensionStatement(GeneratedYangParser.ExtensionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitExtensionStatement(GeneratedYangParser.ExtensionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterExtensionBody(GeneratedYangParser.ExtensionBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitExtensionBody(GeneratedYangParser.ExtensionBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterArgumentStatement(GeneratedYangParser.ArgumentStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitArgumentStatement(GeneratedYangParser.ArgumentStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterArgumentBody(GeneratedYangParser.ArgumentBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitArgumentBody(GeneratedYangParser.ArgumentBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterYinElementStatement(GeneratedYangParser.YinElementStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitYinElementStatement(GeneratedYangParser.YinElementStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterIdentityStatement(GeneratedYangParser.IdentityStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitIdentityStatement(GeneratedYangParser.IdentityStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterIdentityBody(GeneratedYangParser.IdentityBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitIdentityBody(GeneratedYangParser.IdentityBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterBaseStatement(GeneratedYangParser.BaseStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitBaseStatement(GeneratedYangParser.BaseStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterFeatureStatement(GeneratedYangParser.FeatureStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitFeatureStatement(GeneratedYangParser.FeatureStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterFeatureBody(GeneratedYangParser.FeatureBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitFeatureBody(GeneratedYangParser.FeatureBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterDataDefStatement(GeneratedYangParser.DataDefStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitDataDefStatement(GeneratedYangParser.DataDefStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterIfFeatureStatement(GeneratedYangParser.IfFeatureStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitIfFeatureStatement(GeneratedYangParser.IfFeatureStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterUnitsStatement(GeneratedYangParser.UnitsStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitUnitsStatement(GeneratedYangParser.UnitsStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterTypedefStatement(GeneratedYangParser.TypedefStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitTypedefStatement(GeneratedYangParser.TypedefStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterTypeStatement(GeneratedYangParser.TypeStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitTypeStatement(GeneratedYangParser.TypeStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterTypeBodyStatements(GeneratedYangParser.TypeBodyStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitTypeBodyStatements(GeneratedYangParser.TypeBodyStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterNumericalRestrictions(GeneratedYangParser.NumericalRestrictionsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitNumericalRestrictions(GeneratedYangParser.NumericalRestrictionsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRangeStatement(GeneratedYangParser.RangeStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRangeStatement(GeneratedYangParser.RangeStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterCommonStatements(GeneratedYangParser.CommonStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitCommonStatements(GeneratedYangParser.CommonStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterStringRestrictions(GeneratedYangParser.StringRestrictionsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitStringRestrictions(GeneratedYangParser.StringRestrictionsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterLengthStatement(GeneratedYangParser.LengthStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitLengthStatement(GeneratedYangParser.LengthStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterPatternStatement(GeneratedYangParser.PatternStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitPatternStatement(GeneratedYangParser.PatternStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterDefaultStatement(GeneratedYangParser.DefaultStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitDefaultStatement(GeneratedYangParser.DefaultStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterEnumSpecification(GeneratedYangParser.EnumSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitEnumSpecification(GeneratedYangParser.EnumSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterEnumStatement(GeneratedYangParser.EnumStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitEnumStatement(GeneratedYangParser.EnumStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterEnumStatementBody(GeneratedYangParser.EnumStatementBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitEnumStatementBody(GeneratedYangParser.EnumStatementBodyContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterLeafrefSpecification(GeneratedYangParser.LeafrefSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitLeafrefSpecification(GeneratedYangParser.LeafrefSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterPathStatement(GeneratedYangParser.PathStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitPathStatement(GeneratedYangParser.PathStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRequireInstanceStatement(GeneratedYangParser.RequireInstanceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRequireInstanceStatement(GeneratedYangParser.RequireInstanceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterInstanceIdentifierSpecification(GeneratedYangParser.InstanceIdentifierSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitInstanceIdentifierSpecification(GeneratedYangParser.InstanceIdentifierSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterIdentityrefSpecification(GeneratedYangParser.IdentityrefSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitIdentityrefSpecification(GeneratedYangParser.IdentityrefSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterUnionSpecification(GeneratedYangParser.UnionSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitUnionSpecification(GeneratedYangParser.UnionSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterBitsSpecification(GeneratedYangParser.BitsSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitBitsSpecification(GeneratedYangParser.BitsSpecificationContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterBitStatement(GeneratedYangParser.BitStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitBitStatement(GeneratedYangParser.BitStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterBitBodyStatement(GeneratedYangParser.BitBodyStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitBitBodyStatement(GeneratedYangParser.BitBodyStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterPositionStatement(GeneratedYangParser.PositionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitPositionStatement(GeneratedYangParser.PositionStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterStatusStatement(GeneratedYangParser.StatusStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitStatusStatement(GeneratedYangParser.StatusStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterConfigStatement(GeneratedYangParser.ConfigStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitConfigStatement(GeneratedYangParser.ConfigStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterMandatoryStatement(GeneratedYangParser.MandatoryStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitMandatoryStatement(GeneratedYangParser.MandatoryStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterPresenceStatement(GeneratedYangParser.PresenceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitPresenceStatement(GeneratedYangParser.PresenceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterOrderedByStatement(GeneratedYangParser.OrderedByStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitOrderedByStatement(GeneratedYangParser.OrderedByStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterMustStatement(GeneratedYangParser.MustStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitMustStatement(GeneratedYangParser.MustStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterErrorMessageStatement(GeneratedYangParser.ErrorMessageStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitErrorMessageStatement(GeneratedYangParser.ErrorMessageStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterErrorAppTagStatement(GeneratedYangParser.ErrorAppTagStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitErrorAppTagStatement(GeneratedYangParser.ErrorAppTagStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterMinElementsStatement(GeneratedYangParser.MinElementsStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitMinElementsStatement(GeneratedYangParser.MinElementsStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterMaxElementsStatement(GeneratedYangParser.MaxElementsStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitMaxElementsStatement(GeneratedYangParser.MaxElementsStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterMaxValueArgument(GeneratedYangParser.MaxValueArgumentContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitMaxValueArgument(GeneratedYangParser.MaxValueArgumentContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterValueStatement(GeneratedYangParser.ValueStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitValueStatement(GeneratedYangParser.ValueStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterGroupingStatement(GeneratedYangParser.GroupingStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitGroupingStatement(GeneratedYangParser.GroupingStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterContainerStatement(GeneratedYangParser.ContainerStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitContainerStatement(GeneratedYangParser.ContainerStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterLeafStatement(GeneratedYangParser.LeafStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitLeafStatement(GeneratedYangParser.LeafStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterLeafListStatement(GeneratedYangParser.LeafListStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitLeafListStatement(GeneratedYangParser.LeafListStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterListStatement(GeneratedYangParser.ListStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitListStatement(GeneratedYangParser.ListStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterKeyStatement(GeneratedYangParser.KeyStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitKeyStatement(GeneratedYangParser.KeyStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterUniqueStatement(GeneratedYangParser.UniqueStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitUniqueStatement(GeneratedYangParser.UniqueStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterChoiceStatement(GeneratedYangParser.ChoiceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitChoiceStatement(GeneratedYangParser.ChoiceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterShortCaseStatement(GeneratedYangParser.ShortCaseStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitShortCaseStatement(GeneratedYangParser.ShortCaseStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterCaseStatement(GeneratedYangParser.CaseStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitCaseStatement(GeneratedYangParser.CaseStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterUsesStatement(GeneratedYangParser.UsesStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitUsesStatement(GeneratedYangParser.UsesStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRefineStatement(GeneratedYangParser.RefineStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRefineStatement(GeneratedYangParser.RefineStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRefineContainerStatements(GeneratedYangParser.RefineContainerStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRefineContainerStatements(GeneratedYangParser.RefineContainerStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRefineLeafStatements(GeneratedYangParser.RefineLeafStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRefineLeafStatements(GeneratedYangParser.RefineLeafStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRefineLeafListStatements(GeneratedYangParser.RefineLeafListStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRefineLeafListStatements(GeneratedYangParser.RefineLeafListStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRefineListStatements(GeneratedYangParser.RefineListStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRefineListStatements(GeneratedYangParser.RefineListStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRefineChoiceStatements(GeneratedYangParser.RefineChoiceStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRefineChoiceStatements(GeneratedYangParser.RefineChoiceStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRefineCaseStatements(GeneratedYangParser.RefineCaseStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRefineCaseStatements(GeneratedYangParser.RefineCaseStatementsContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterUsesAugmentStatement(GeneratedYangParser.UsesAugmentStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitUsesAugmentStatement(GeneratedYangParser.UsesAugmentStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterAugmentStatement(GeneratedYangParser.AugmentStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitAugmentStatement(GeneratedYangParser.AugmentStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterWhenStatement(GeneratedYangParser.WhenStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitWhenStatement(GeneratedYangParser.WhenStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterRpcStatement(GeneratedYangParser.RpcStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitRpcStatement(GeneratedYangParser.RpcStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterInputStatement(GeneratedYangParser.InputStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitInputStatement(GeneratedYangParser.InputStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterOutputStatement(GeneratedYangParser.OutputStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitOutputStatement(GeneratedYangParser.OutputStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterNotificationStatement(GeneratedYangParser.NotificationStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitNotificationStatement(GeneratedYangParser.NotificationStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterDeviationStatement(GeneratedYangParser.DeviationStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitDeviationStatement(GeneratedYangParser.DeviationStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterDeviateNotSupportedStatement(GeneratedYangParser.DeviateNotSupportedStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitDeviateNotSupportedStatement(GeneratedYangParser.DeviateNotSupportedStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterDeviateAddStatement(GeneratedYangParser.DeviateAddStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitDeviateAddStatement(GeneratedYangParser.DeviateAddStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterDeviateDeleteStatement(GeneratedYangParser.DeviateDeleteStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitDeviateDeleteStatement(GeneratedYangParser.DeviateDeleteStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterDeviateReplaceStatement(GeneratedYangParser.DeviateReplaceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitDeviateReplaceStatement(GeneratedYangParser.DeviateReplaceStatementContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterString(GeneratedYangParser.StringContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitString(GeneratedYangParser.StringContext ctx) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void visitTerminal(TerminalNode terminalNode) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void visitErrorNode(ErrorNode errorNode) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void enterEveryRule(ParserRuleContext parserRuleContext) {
+        //TODO: implement the method.
+    }
+
+    @Override
+    public void exitEveryRule(ParserRuleContext parserRuleContext) {
+        //TODO: implement the method.
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/package-info.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/package-info.java
new file mode 100644
index 0000000..66d09d1
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Provide call back functions for listeners based tree walk.
+ */
+package org.onosproject.yangutils.parser.impl.listeners;
\ No newline at end of file
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerError.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerError.java
new file mode 100644
index 0000000..d4c8504
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/ListenerError.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.parserutils;
+
+/**
+ * Error information while doing a listener's based walk is maintained in it.
+ */
+public class ListenerError {
+
+    // Maintains the state of Exception.
+    private boolean errorFlag = false;
+
+    // Maintains the reason of Exception.
+    private String errorMsg;
+
+    /**
+     * Returns error flag.
+     *
+     * @return error flag.
+     */
+    public boolean isErrorFlag() {
+        return errorFlag;
+    }
+
+    /**
+     * Returns error message.
+     *
+     * @return error msg.
+     */
+    public String getErrorMsg() {
+        return errorMsg;
+    }
+
+    /**
+     * Set error flag.
+     *
+     * @param errorFlag error existence flag
+     */
+    public void setErrorFlag(boolean errorFlag) {
+        this.errorFlag = errorFlag;
+    }
+
+    /**
+     * Set error message.
+     *
+      * @param errorMsg reason for error.
+     */
+    public void setErrorMsg(String errorMsg) {
+        this.errorMsg = errorMsg;
+    }
+}
\ No newline at end of file
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/package-info.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/package-info.java
new file mode 100644
index 0000000..b2127e9
--- /dev/null
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/parserutils/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Provide common utils for parser implementation.
+ */
+package org.onosproject.yangutils.parser.impl.parserutils;
\ No newline at end of file