MPLS label selector and treatment

Change-Id: Id1fba1e04155e6d97de4c8fd95573641537f1b7a
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/TrafficSelector.java b/core/api/src/main/java/org/onlab/onos/net/flow/TrafficSelector.java
index ac75147..daf5268 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/TrafficSelector.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/TrafficSelector.java
@@ -146,6 +146,14 @@
          */
         public Builder matchTcpDst(Short tcpPort);
 
+
+        /**
+         * Matches on a MPLS label .
+         * @param mplsLabel a MPLS label.
+         * @return a selection builder
+         */
+        public Builder matchMplsLabel(Integer mplsLabel);
+
         /**
          * Matches an optical signal ID or lambda.
          *