:sig
bool ws_close(String connection_id = "")

:params
connection_id : optional target client ID, defaults to the current WebSocket client
return value : true if the target connection exists and was scheduled to close

:desc
Queues a WebSocket close frame and closes the targeted connection.

If `connection_id` is omitted, the current connection handled by `WS()` is closed.

:see
>websocket