ONOS-7000 P4 tutorial application and P4 program

Change-Id: Ia0a6befa6374a1950485c1fba0cfacb5ff4ce52c
diff --git a/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java b/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java
index 487380f..d0a4732 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/criteria/PiCriterion.java
@@ -342,7 +342,7 @@
          *
          * @return PiCriterion
          */
-        public Criterion build() {
+        public PiCriterion build() {
             ImmutableMap<PiHeaderFieldId, PiFieldMatch> fieldMatchMap = fieldMatchMapBuilder.build();
             checkArgument(fieldMatchMap.size() > 0, "Cannot build PI criterion with 0 field matches");
             return new PiCriterion(fieldMatchMap);