code: protected static void notifyListener(
              EventExecutor eventExecutor, final Future<?> future, final GenericFutureListener<?> listener) {
          checkNotNull(eventExecutor, "eventExecutor");
          checkNotNull(future, "future");
          checkNotNull(listener, "listener");
          notifyListenerWithStackOverFlowProtection(eventExecutor, future, listener);
      }
docs: Notify a listener that a future has completed.
  <p>
  This method has a fixed depth of {@link #MAX_LISTENER_STACK_DEPTH} that will limit recursion to prevent
  {@link StackOverflowError} and will stop notifying listeners added after this threshold is exceeded.
  @param eventExecutor the executor to use to notify the listener {@code listener}.
  @param future the future that is complete.
  @param listener the listener to notify.