Use the NOOP class to implement the NOOP constant.

Really, they should both be deprecated. Log your exceptions.
If there's a special place where you have to hack it to not log
an exception, that special place can damn well create its own no-op
listener. Or be fixed!

Having an abstract class that only implements a blank requestCompleted()
would make sense, as would a sharable singleton instance that does
nothing on success and always logs on failure. Hmm.

src/main/java/com/samskivert/util/ResultListener.java

@@ -61,10 +61,5 @@ public interface ResultListener<T>
 
     /** @deprecated This cannot be type safe so don't use it. */
     @Deprecated
-    public ResultListener<Object> NOOP = new ResultListener<Object>() {
-        public void requestCompleted (Object result) {
-        }
-        public void requestFailed (Exception cause) {
-        }
-    };
+    public ResultListener<Object> NOOP = new NOOP<Object>();
 }