YANG string restriction listener + YANG Range restriction listener review comment fix

Change-Id: I9e7af9c67f8fbf918d4e0d8ff147a560889ff264
diff --git a/utils/yangutils/src/test/resources/ValidPatternStatement.yang b/utils/yangutils/src/test/resources/ValidPatternStatement.yang
new file mode 100644
index 0000000..556db31
--- /dev/null
+++ b/utils/yangutils/src/test/resources/ValidPatternStatement.yang
@@ -0,0 +1,10 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type string {
+            pattern "[a-zA-Z]";
+         }
+    }
+}