message: Returned no animation if empty stirng
  Not strictly necessary becuase getIdentified will return 0. But it's clearer now taking empty stirng as no animation
diff: @@ -48,6 +48,8 @@ abstract class SceneNavigator {
  }
  if (animationName == null)
  return defaultAnimation.get(defaultId);
  + if (animationName.equals(""))
  + return 0;
  String packageName = context.getPackageName();
  return context.getResources().getIdentifier(animationName, "anim", packageName);
  }
  