Method WriteNext

cpp/src/arrow/dataset/dataset_writer.cc:244–253

 private:
  Future<> WriteNext(std::shared_ptr<RecordBatch> next) {
    // May want to prototype / measure someday pushing the async write down further
    return DeferNotOk(options_.filesystem->io_context().executor()->Submit(
        [self = shared_from_this(), batch = std::move(next)]() {
          int64_t rows_to_release = batch->num_rows();
          Status status = self->writer_->Write(batch);
          self->writer_state_->rows_in_flight_throttle.Release(rows_to_release);
          return status;
        }));
  }

  Future<> DoFinish() {
    {