Move static factory methods to the utility class

Change-Id: Icf458adf78f51823e4ffa31346595fa9716485bf
diff --git a/core/api/src/main/java/org/onosproject/net/newresource/DiscreteResourceId.java b/core/api/src/main/java/org/onosproject/net/newresource/DiscreteResourceId.java
index 804dfba..4b83344 100644
--- a/core/api/src/main/java/org/onosproject/net/newresource/DiscreteResourceId.java
+++ b/core/api/src/main/java/org/onosproject/net/newresource/DiscreteResourceId.java
@@ -50,14 +50,14 @@
     public DiscreteResourceId child(Object child) {
         checkArgument(!(child instanceof Class<?>));
 
-        return Resource.discrete(this, child).id();
+        return Resources.discrete(this, child).id();
     }
 
     @Override
     public ContinuousResourceId child(Class<?> child) {
         checkNotNull(child);
 
-        return Resource.continuous(this, child).id();
+        return Resources.continuous(this, child).id();
     }
 
     @Override