public static <V extends @Nullable Object> ListenableFuture<V> immediateFuture(
      @ParametricNullness V value) {
    if (value == null) {
      // This cast is safe because null is assignable to V for all V (i.e. it is bivariant)
      @SuppressWarnings("unchecked")
      ListenableFuture<V> typedNull = (ListenableFuture<V>) ImmediateFuture.NULL;
      return typedNull;
    }
    return new ImmediateFuture<>(value);
  }

  /**