For testing only - deliberately splits messages into two pieces and sends them separately - this
is VERY VERY useful for testing whether a JVM on the other end using NIO is correctly merging
packets into complete messages (NB: even a NIO server in blocking mode will still occasionally
receive split messages due to the internet)
Stops the server - not immediately (attempts immediate stop, but the server will have to finish
some processing and close down some native OS resources, which takes time)