public static <INFO> ControllerListener<INFO> getNoOpListener() {
    // Listener only receives <INFO>, it never produces one.
    // That means if it can accept Object, it can very well accept <INFO>.
    return (ControllerListener<INFO>) NO_OP_LISTENER;
  }
Convenience class that has empty implementation of {@link ControllerListener}.
drawee/src/main/java/com/facebook/drawee/controller/BaseControllerListener.java