Favor adapter classes over service interfaces in unit tests

In unit tests that are mocking an entire interface, instead
extend the Adapter class so the unused method overrides
are no longer needed.

Change-Id: I6e332cc5cb59410f163deea223fbc94e73d83917
diff --git a/core/net/src/test/java/org/onosproject/net/intent/impl/MockFlowRuleService.java b/core/net/src/test/java/org/onosproject/net/intent/impl/MockFlowRuleService.java
index 66ea27e..27e523d 100644
--- a/core/net/src/test/java/org/onosproject/net/intent/impl/MockFlowRuleService.java
+++ b/core/net/src/test/java/org/onosproject/net/intent/impl/MockFlowRuleService.java
@@ -23,14 +23,13 @@
 import org.onosproject.net.flow.DefaultFlowEntry;
 import org.onosproject.net.flow.FlowEntry;
 import org.onosproject.net.flow.FlowRule;
-import org.onosproject.net.flow.FlowRuleListener;
 import org.onosproject.net.flow.FlowRuleOperations;
-import org.onosproject.net.flow.FlowRuleService;
+import org.onosproject.net.flow.FlowRuleServiceAdapter;
 
 import com.google.common.collect.Sets;
 
 
-public class MockFlowRuleService implements FlowRuleService {
+public class MockFlowRuleService extends FlowRuleServiceAdapter {
 
     final Set<FlowRule> flows = Sets.newHashSet();
     boolean success;
@@ -62,16 +61,6 @@
     }
 
     @Override
-    public void addListener(FlowRuleListener listener) {
-        //TODO not implemented
-    }
-
-    @Override
-    public void removeListener(FlowRuleListener listener) {
-        //TODO not implemented
-    }
-
-    @Override
     public int getFlowRuleCount() {
         return flows.size();
     }
@@ -99,11 +88,6 @@
     }
 
     @Override
-    public void removeFlowRulesById(ApplicationId appId) {
-        //TODO not implemented
-    }
-
-    @Override
     public Iterable<FlowRule> getFlowRulesById(ApplicationId id) {
         return flows.stream()
                     .filter(flow -> flow.appId() == id.id())