void close([int code, String reason ])

Source 

void close([int code, String reason]) {
  if (reason != null) {
    _blink.BlinkWebSocket.instance.close_Callback_2_(this, code, reason);
    return;
  }
  if (code != null) {
    _blink.BlinkWebSocket.instance.close_Callback_1_(this, code);
    return;
  }
  _blink.BlinkWebSocket.instance.close_Callback_0_(this);
  return;
}