public static <INFO> InternalForwardingListener<INFO> createInternal(
        ControllerListener<? super INFO> listener1, ControllerListener<? super INFO> listener2) {
      if (FrescoSystrace.isTracing()) {
        FrescoSystrace.beginSection("AbstractDraweeController#createInternal");
      }
      InternalForwardingListener<INFO> forwarder = new InternalForwardingListener<INFO>();
      forwarder.addListener(listener1);
      forwarder.addListener(listener2);
      if (FrescoSystrace.isTracing()) {
        FrescoSystrace.endSection();
      }
      return forwarder;
    }
This class is used to allow an optimization of not creating a ForwardingControllerListener when
there is only a single controller listener.
drawee/src/main/java/com/facebook/drawee/controller/AbstractDraweeController.java