[ONOS-3391] create arp_spa selector to onos

Change-Id: I2508a3ca7acb95b9792f0b23e085074a5b030a3b
diff --git a/core/api/src/main/java/org/onosproject/net/flow/TrafficSelector.java b/core/api/src/main/java/org/onosproject/net/flow/TrafficSelector.java
index 6b1720b..9fe88d5 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/TrafficSelector.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/TrafficSelector.java
@@ -395,6 +395,14 @@
         Builder matchArpTpa(Ip4Address addr);
 
         /**
+         * Matches a arp IPv4 source address.
+         *
+         * @param addr a arp IPv4 source address
+         * @return a selection builder
+         */
+        Builder matchArpSpa(Ip4Address addr);
+
+        /**
          * Matches a arp_eth_dst address.
          *
          * @param addr a arp_eth_dst address