Handles the MessageBody part of writing a chunk of data to the network.
Normally this is a no-op, but if you have set this's accumulate flag to
false, then this will cause chunk to be discarded to free up memory.
This is a low-level method which you should not need to use, and there are further restrictions on its proper use which are not documented here.
| this | |
| chunk |
a Bytes returned from [[email protected]_chunk] |