code: func (s *Server) proxy(w http.ResponseWriter, r *http.Request) {
  	if r.Method != http.MethodConnect {
  		http.Error(w, "", http.StatusMethodNotAllowed)
  		return
  	}
  
  	dst, err := net.Dial("tcp", s.URL.Host)
  	if err != nil {
  		http.Error(w, err.Error(), http.StatusBadGateway)
  		return
  	}
  	w.WriteHeader(http.StatusOK)
  
  	src, _, err := w.(http.Hijacker).Hijack()
  	if err != nil {
  		http.Error(w, err.Error(), http.StatusBadRequest)
  		return
  	}
  
  	go io.Copy(src, dst)
  	go func() {
  		_, _ = io.Copy(dst, src)
  		_ = dst.Close()
  		_ = src.Close()
  	}()
  }
docs: // proxy tunnels SDK requests