presto-main/src/main/java/io/prestosql/execution/buffer/BroadcastOutputBuffer.java/BroadcastOutputBuffer/get
class BroadcastOutputBuffer:    @Override
    public ListenableFuture<BufferResult> get(OutputBufferId outputBufferId, long startingSequenceId, DataSize maxSize)
    {
        checkState(!Thread.holdsLock(this), "Can not get pages while holding a lock on this");
        requireNonNull(outputBufferId, "outputBufferId is null");
        checkArgument(maxSize.toBytes() > 0, "maxSize must be at least 1 byte");

        return getBuffer(outputBufferId).getPages(startingSequenceId, maxSize);
    }