Change to static import for lesser indentation.

Change-Id: I5350c65496023a96c88cefe9dd5ed64a72c5f30c
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 b63f901..a771307 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
@@ -18,14 +18,17 @@
 
 import org.onosproject.yangutils.datamodel.YangContainer;
 import org.onosproject.yangutils.parser.Parsable;
-import org.onosproject.yangutils.parser.ParsableDataType;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
-import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation;
-import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction;
-import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType;
-import org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation;
+
+import static org.onosproject.yangutils.parser.ParsableDataType.PRESENCE_DATA;
+import static org.onosproject.yangutils.parser.ParsableDataType.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;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -61,20 +64,15 @@
                                              GeneratedYangParser.PresenceStatementContext ctx) {
 
         // Check for stack to be non empty.
-        ListenerValidation.checkStackIsNotEmpty(listener, ListenerErrorType.MISSING_HOLDER,
-                ParsableDataType.PRESENCE_DATA, String.valueOf(ctx.string().getText()),
-                ListenerErrorLocation.ENTRY);
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, PRESENCE_DATA, ctx.string().getText(), ENTRY);
 
         Parsable tmpData = listener.getParsedDataStack().peek();
-        if (tmpData.getParsableDataType() == ParsableDataType.CONTAINER_DATA) {
+        if (tmpData.getParsableDataType() == CONTAINER_DATA) {
             YangContainer container = (YangContainer) tmpData;
             container.setPresence(ctx.string().getText());
         } else {
-            throw new ParserException(ListenerErrorMessageConstruction
-                    .constructListenerErrorMessage(ListenerErrorType.INVALID_HOLDER,
-                            ParsableDataType.PRESENCE_DATA,
-                            String.valueOf(ctx.string().getText()),
-                            ListenerErrorLocation.ENTRY));
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, PRESENCE_DATA,
+                    ctx.string().getText(), ENTRY));
         }
     }
 }
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