fails:Socket::BasicSocket#close_write closes the writing end of the socket
fails:Socket::BasicSocket#close_write works on sockets with closed write ends
fails:Socket::BasicSocket#close_write does not close the socket
fails:Socket::BasicSocket#close_write fully closes the socket if it was already closed for reading
fails:Socket::BasicSocket#close_write raises IOError on closed socket
fails:Socket::BasicSocket#close_write returns nil
