Added fixme notes. This is not a sustainable approach!

Change-Id: Ia4c798854003d9ea5dc6083ef691cb59a309ac1b
diff --git a/runtime/api/src/main/java/org/onosproject/yang/runtime/api/YangRuntimeService.java b/runtime/api/src/main/java/org/onosproject/yang/runtime/api/YangRuntimeService.java
index ef966cf..747907c 100644
--- a/runtime/api/src/main/java/org/onosproject/yang/runtime/api/YangRuntimeService.java
+++ b/runtime/api/src/main/java/org/onosproject/yang/runtime/api/YangRuntimeService.java
@@ -47,6 +47,8 @@
      * node information
      * @throws YangRuntimeException when fails to perform decode operation
      */
+    // FIXME: This needs to be revised for symmetry with encode and mutability
+    // FIXME: Entities exchanged across this boundary ought not to be mutable
     DecodedOutput decode(CompositeStream external, String dataFormat,
                          boolean nodeAnnotated);
 
@@ -76,6 +78,7 @@
      * configuration data
      * @throws YangRuntimeException when fails to perform encode operation
      */
+    // FIXME: Entities exchanged across this boundary ought not to be mutable
     CompositeStream encode(CompositeData internal, String dataFormat,
                            List<AnnotatedNodeInfo> info);
 }