code: func (c *Client) Listen(n, addr string) (net.Listener, error) {
  	laddr, err := net.ResolveTCPAddr(n, addr)
  	if err != nil {
  		return nil, err
  	}
  	return c.ListenTCP(laddr)
  }
docs: // Listen requests the remote peer open a listening socket on
  // addr. Incoming connections will be available by calling Accept on
  // the returned net.Listener. The listener must be serviced, or the
  // SSH connection may hang.