serializer helper fix and data node walker

Change-Id: I46c0b0228370044b2f56c4fe5fafeb6cd11bfff2
diff --git a/runtime/src/test/resources/schemaProviderTestYangFiles/list.yang b/runtime/src/test/resources/schemaProviderTestYangFiles/list.yang
index 122ce11..2ff07dc 100644
--- a/runtime/src/test/resources/schemaProviderTestYangFiles/list.yang
+++ b/runtime/src/test/resources/schemaProviderTestYangFiles/list.yang
@@ -29,7 +29,7 @@
             }
 
             container c1 {
-                leaf l1 {
+                leaf leaf_c1 {
                   type string;
                 }
             }