YANG Grouping Linker Support

Change-Id: I2fec0c0bb4d1584e82ffba3228106897ccad2bf5
diff --git a/src/test/resources/ValidNotificationStatement.yang b/src/test/resources/ValidNotificationStatement.yang
index d588bb9..072df23 100644
--- a/src/test/resources/ValidNotificationStatement.yang
+++ b/src/test/resources/ValidNotificationStatement.yang
@@ -2,6 +2,9 @@
     namespace "http://example.net/rock";
     prefix "rock";
 
+    import ietf-yang-types {
+             prefix "P";
+         }
     notification link-failure {
         description "A link failure has been detected";
         status deprecated;