Added getCriterion method to TrafficSelector

Change-Id: I72d89d878e1fae95d1e16d9ed473b7711895e478
diff --git a/core/net/src/test/java/org/onlab/onos/net/intent/IntentTestsMocks.java b/core/net/src/test/java/org/onlab/onos/net/intent/IntentTestsMocks.java
index 0f020a4..e0e49ef 100644
--- a/core/net/src/test/java/org/onlab/onos/net/intent/IntentTestsMocks.java
+++ b/core/net/src/test/java/org/onlab/onos/net/intent/IntentTestsMocks.java
@@ -1,5 +1,7 @@
 package org.onlab.onos.net.intent;
 
+import static org.onlab.onos.net.NetTestTools.createPath;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -12,12 +14,11 @@
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 import org.onlab.onos.net.flow.criteria.Criterion;
+import org.onlab.onos.net.flow.criteria.Criterion.Type;
 import org.onlab.onos.net.flow.instructions.Instruction;
 import org.onlab.onos.net.topology.LinkWeight;
 import org.onlab.onos.net.topology.PathService;
 
-import static org.onlab.onos.net.NetTestTools.createPath;
-
 /**
  * Common mocks used by the intent framework tests.
  */
@@ -30,6 +31,11 @@
         public Set<Criterion> criteria() {
             return new HashSet<>();
         }
+
+        @Override
+        public Criterion getCriterion(Type type) {
+            return null;
+        }
     }
 
     /**