private static @NotNull IntPredicate getPredicateOutOfFileSetObject(@Nullable Object input) {
    if (input == null) return __ -> false;

    if (input instanceof Integer) {
      final int singleId = (Integer)input;

      return id -> id == singleId;
    }
    return ((ChangeBufferingList)input).intPredicate();
  }
private static @NotNull IntPredicate getPredicateOutOfFileSetObject(@Nullable Object input)