code: private void readClose(FrameIn fIs)
      throws IOException
    {
      if (_state.isClosed()) {
        return;
      }
  
      _state = _state.closePeer();
  
      int code = fIs.readClose();
  
      StringBuilder sb = new StringBuilder();
      fIs.readText(sb);
  
      if (_service != null) {
        WebSocketClose codeWs = WebSocketCloses.of(code);
  
        try {
          _service.close(codeWs, sb.toString(), this);
        } catch (Exception e) {
          throw new IOException(e);
        }
      }
      else {
        close();
      }
  
      if (_state.isClosed()) {
        disconnect();
      }
      //System.out.println("READ_C: " + code + " " + sb);;
    }
docs: Read a close frame.