ONOS-2692: Implement methods to unregister resources

Change-Id: Iae88207c5edecf6645aeff3c15875178b5266634
diff --git a/core/net/src/main/java/org/onosproject/net/newresource/impl/ResourceManager.java b/core/net/src/main/java/org/onosproject/net/newresource/impl/ResourceManager.java
index f2a9286..abce072 100644
--- a/core/net/src/main/java/org/onosproject/net/newresource/impl/ResourceManager.java
+++ b/core/net/src/main/java/org/onosproject/net/newresource/impl/ResourceManager.java
@@ -130,4 +130,10 @@
         List<ResourcePath> resources = Lists.transform(children, x -> ResourcePath.child(parent, x));
         return store.register(parent, resources);
     }
+
+    @Override
+    public <T> boolean unregisterResources(ResourcePath parent, List<T> children) {
+        List<ResourcePath> resources = Lists.transform(children, x -> ResourcePath.child(parent, x));
+        return store.unregister(parent, resources);
+    }
 }