YANG construct collision detection framework added

Change-Id: I1458f9e3192641f3f90c444798c31a64536ffa5d
diff --git a/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListenerTest.java b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListenerTest.java
index c4b9fa7..53611fe 100644
--- a/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListenerTest.java
+++ b/utils/yangutils/src/test/java/org/onosproject/yangutils/parser/impl/listeners/UnitsListenerTest.java
@@ -157,7 +157,7 @@
     @Test
     public void processUnitsStatementCardinality() throws IOException, ParserException {
         thrown.expect(ParserException.class);
-        thrown.expectMessage("Internal parser error detected: Invalid cardinality in units before processing.");
+        thrown.expectMessage("YANG file error: Invalid cardinality of units in leaf \"invalid-interval\".");
         YangNode node = manager.getDataModel("src/test/resources/UnitsStatementCardinality.yang");
     }