-record(websocket_handler, {
    on_close :: gleam@option:option(fun((gleam@otp@process:sender(glisten@tcp:handler_message())) -> nil)),
    on_init :: gleam@option:option(fun((gleam@otp@process:sender(glisten@tcp:handler_message())) -> nil)),
    handler :: fun((mist@websocket:message(), glisten@tcp:socket()) -> {ok, nil} |
        {error, nil})
}).