- WEBSOCKET_OP_CONTINUE- WEBSOCKET_OP_TEXT- WEBSOCKET_OP_BINARY- WEBSOCKET_OP_CLOSE- WEBSOCKET_OP_PING- WEBSOCKET_OP_PONGOrred with one of the flags:- WEBSOCKET_DONT_FIN: Don't set the FIN flag on the frame to be sent.`data` and `data_len` contain frame data.