adding support of WCMP weights to Next Objective

Change-Id: Id8f9a4222d0d9d98995f727dbfbf467ab2104468
diff --git a/core/api/src/main/java/org/onosproject/net/flowobjective/NextTreatment.java b/core/api/src/main/java/org/onosproject/net/flowobjective/NextTreatment.java
index af849a2..cdeff98 100644
--- a/core/api/src/main/java/org/onosproject/net/flowobjective/NextTreatment.java
+++ b/core/api/src/main/java/org/onosproject/net/flowobjective/NextTreatment.java
@@ -19,6 +19,7 @@
  * Represents next action in the NextObjective.
  */
 public interface NextTreatment {
+    int DEFAULT_WEIGHT = 1;
     /**
      * Types of next action.
      */
@@ -40,4 +41,10 @@
      * @return type
      */
     Type type();
+    /**
+     * weight of this next action.
+     *
+     * @return weight
+     */
+    int weight();
 }