code: func proxyTCP(in, out *net.TCPConn) {
  	var wg sync.WaitGroup
  	wg.Add(2)
  	klog.V(4).Infof("Creating proxy between %v <-> %v <-> %v <-> %v",
  		in.RemoteAddr(), in.LocalAddr(), out.LocalAddr(), out.RemoteAddr())
  	go copyBytes("from backend", in, out, &wg)
  	go copyBytes("to backend", out, in, &wg)
  	wg.Wait()
  }
docs: // proxyTCP proxies data bi-directionally between in and out.