- flush message reply! error!procedure
This corresponds to a 9P Tflush request. The message is a list of one element, the tag of the operation to flush. This is not currently well-supported by the 9p-server implementation, as the tags of operations are not currently exposed to handlers.
If the flush succeeds, it should call reply! with an empty list. If not, it can call error! with an error string.
The default implementation calls its reply! callback with an empty list.