async fn check_result<I1: HummockIterator<Direction = Forward>, I2: HummockIterator<Direction = Forward>>(
left_iter: UserIterator<I1>,
right_iter: UserIterator<I2>,
) -> HummockResult<bool>
async fn check_result<I1: HummockIterator<Direction = Forward>, I2: HummockIterator<Direction = Forward>>(
left_iter: UserIterator<I1>,
right_iter: UserIterator<I2>,
) -> HummockResult<bool>