code: func (w *WSAcceptor) ListenAndServe() {
  	if w.hasTLSCertificates() {
  		w.ListenAndServeTLS(w.certFile, w.keyFile)
  		return
  	}
  
  	var upgrader = websocket.Upgrader{
  		ReadBufferSize:  1024,
  		WriteBufferSize: 1024,
  		CheckOrigin: func(r *http.Request) bool {
  			return true
  		},
  	}
  
  	listener, err := net.Listen("tcp", w.addr)
  	if err != nil {
  		logger.Log.Fatalf("Failed to listen: %s", err.Error())
  	}
  	w.listener = listener
  
  	w.serve(&upgrader)
  }
docs: // ListenAndServe listens and serve in the specified addr