presto-main/src/main/java/io/prestosql/execution/SqlTask.java/SqlTask/getTaskResults
class SqlTask:    public ListenableFuture<BufferResult> getTaskResults(OutputBufferId bufferId, long startingSequenceId, DataSize maxSize)
    {
        requireNonNull(bufferId, "bufferId is null");
        checkArgument(maxSize.toBytes() > 0, "maxSize must be at least 1 byte");

        return outputBuffer.get(bufferId, startingSequenceId, maxSize);
    }