closemessage if this was not already sent and wait for the close reply.
|Code||is the numerical code indicating the close status. This is 16-bit integer. The codes are defined in section 7.4.1. Defined Status Codes of RFC6455. Notably, 1000 indicates a normal closure.|
|Data||is currently interpreted as text.|
websocket_error(unexpected_message, Reply)if the other side did not send a close message in reply.