code: func (t *TestTLSServer) NewClient(identity TestIdentity) (*Client, error) {
  	tlsConfig, err := t.ClientTLSConfig(identity)
  	if err != nil {
  		return nil, trace.Wrap(err)
  	}
  	addrs := []utils.NetAddr{utils.FromAddr(t.Listener.Addr())}
  	return NewTLSClient(ClientConfig{Addrs: addrs, TLS: tlsConfig})
  }
docs: // NewClient returns new client to test server authenticated with identity