Unit tets for instruction JSON codecs

Fixed several bugs in codecs turned up by unit tests

Change-Id: Icddb31aa3d2cb58612a0578772d24ff5f113d073
diff --git a/web/api/src/test/java/org/onosproject/codec/impl/MockCodecContext.java b/web/api/src/test/java/org/onosproject/codec/impl/MockCodecContext.java
index f54f523..f49e829 100644
--- a/web/api/src/test/java/org/onosproject/codec/impl/MockCodecContext.java
+++ b/web/api/src/test/java/org/onosproject/codec/impl/MockCodecContext.java
@@ -28,6 +28,9 @@
     private ObjectMapper mapper = new ObjectMapper();
     private CodecManager manager = new CodecManager();
 
+    /**
+     * Constructs a new mock codec context.
+     */
     public MockCodecContext() {
         manager.activate();
     }