ONOS-7050 First stab at PI translation store

Change-Id: I7f48802b1f5d70fbe3e6cead2800855de18b9207
diff --git a/core/api/src/main/java/org/onosproject/net/pi/runtime/PiActionGroup.java b/core/api/src/main/java/org/onosproject/net/pi/runtime/PiActionGroup.java
index 1d9a94b..9084bea 100644
--- a/core/api/src/main/java/org/onosproject/net/pi/runtime/PiActionGroup.java
+++ b/core/api/src/main/java/org/onosproject/net/pi/runtime/PiActionGroup.java
@@ -34,7 +34,7 @@
  * Instance of an action group of a protocol-independent pipeline.
  */
 @Beta
-public final class PiActionGroup {
+public final class PiActionGroup implements PiEntity {
 
     private final PiActionGroupId id;
     private final PiActionGroupType type;
@@ -125,6 +125,11 @@
         return new Builder();
     }
 
+    @Override
+    public PiEntityType piEntityType() {
+        return PiEntityType.GROUP;
+    }
+
     /**
      * Builder of action groups.
      */