[ONOS-4941][ONOS-4883][ONOS-4979]Grouping and uses interfile linking issue + defect fix

Change-Id: I5e8145f05d3ef570d4ecbbe885c93de172de0ea3
diff --git a/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangList.java b/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangList.java
index 2b2426a..b86911a 100644
--- a/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangList.java
+++ b/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangList.java
@@ -16,15 +16,14 @@
 
 package org.onosproject.yangutils.datamodel;
 
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
 import org.onosproject.yangutils.datamodel.exceptions.DataModelException;
 import org.onosproject.yangutils.datamodel.utils.Parsable;
 import org.onosproject.yangutils.datamodel.utils.YangConstructType;
 import org.onosproject.yangutils.datamodel.utils.builtindatatype.YangDataTypes;
 
-import java.util.ArrayList;
-import java.util.LinkedList;
-import java.util.List;
-
 import static org.onosproject.yangutils.datamodel.utils.DataModelUtils.detectCollidingChildUtil;
 
 /*
@@ -72,7 +71,7 @@
 public class YangList
         extends YangNode
         implements YangLeavesHolder, YangCommonInfo, Parsable, CollisionDetector,
-        YangAugmentableNode, YangMustHolder, YangIfFeatureHolder, YangDataNode {
+        YangAugmentableNode, YangMustHolder, YangWhenHolder, YangIfFeatureHolder, YangDataNode {
 
     private static final long serialVersionUID = 806201609L;
 
@@ -219,6 +218,7 @@
      *
      * @return the when
      */
+    @Override
     public YangWhen getWhen() {
         return when;
     }
@@ -228,6 +228,7 @@
      *
      * @param when the when to set
      */
+    @Override
     public void setWhen(YangWhen when) {
         this.when = when;
     }
@@ -624,7 +625,6 @@
      * Validates key statement of list.
      *
      * @param leaves    list of leaf attributes of list
-     * @param leafLists list of leaf-list attributes of list
      * @param keys      list of key attributes of list
      * @throws DataModelException a violation of data model rules
      */