presto-main/src/main/java/io/prestosql/execution/buffer/PartitionedOutputBuffer.java/PartitionedOutputBuffer/acknowledge
class PartitionedOutputBuffer:    @Override
    public void acknowledge(OutputBufferId outputBufferId, long sequenceId)
    {
        requireNonNull(outputBufferId, "bufferId is null");

        partitions.get(outputBufferId.getId()).acknowledgePages(sequenceId);
    }