yang choice case translator + whitebox fix

Change-Id: I96f1855bc71a002335946150b51e911ae6ac2fb2
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeRestriction.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeRestriction.java
index 38b48bd..39c2cb5 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeRestriction.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/datamodel/YangRangeRestriction.java
@@ -118,7 +118,7 @@
         if (getAscendingRangeIntervals() == null) {
             throw new DataModelException("No range restriction info");
         }
-        if (getAscendingRangeIntervals().size() == 0) {
+        if (getAscendingRangeIntervals().isEmpty()) {
             throw new DataModelException("No range interval info");
         }
         return getAscendingRangeIntervals().get(0).getStartValue();
@@ -134,7 +134,7 @@
         if (getAscendingRangeIntervals() == null) {
             throw new DataModelException("No range restriction info");
         }
-        if (getAscendingRangeIntervals().size() == 0) {
+        if (getAscendingRangeIntervals().isEmpty()) {
             throw new DataModelException("No range interval info");
         }
         return getAscendingRangeIntervals()
@@ -184,7 +184,7 @@
     public boolean isValidValueString(String valueInString) throws DataModelException {
 
         if (getAscendingRangeIntervals() == null
-                || getAscendingRangeIntervals().size() == 0) {
+                || getAscendingRangeIntervals().isEmpty()) {
             // Throw exception, At least one default range needs to be set in constructor or in linker.
             throw new DataModelException("Range interval missing in range restriction.");