YANG Grouping Linker Support

Change-Id: I2fec0c0bb4d1584e82ffba3228106897ccad2bf5
diff --git a/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java b/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
index ffd8470..fb0ec72 100644
--- a/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
+++ b/src/test/java/org/onosproject/yangutils/parser/impl/listeners/PatternRestrictionListenerTest.java
@@ -108,7 +108,7 @@
         assertThat(yangNode.getName(), is("Test"));
 
         YangTypeDef typedef = (YangTypeDef) yangNode.getChild();
-        YangStringRestriction stringRestriction = (YangStringRestriction) typedef.getDataType()
+        YangStringRestriction stringRestriction = (YangStringRestriction) typedef.getTypeDefBaseType()
                 .getDataTypeExtendedInfo();
 
         YangPatternRestriction yangPatternRestriction = stringRestriction.getPatternRestriction();
@@ -166,4 +166,4 @@
                 .getPatternList().listIterator();
         assertThat(patternListIterator.next(), is("-[0-9]+|[0-9]+"));
     }
-}
\ No newline at end of file
+}