code: func NewClient(requrl string, transport http.RoundTripper) (*Client, error) {
  	if transport == nil {
  		transport = http.DefaultTransport
  	}
  
  	httpClient := &http.Client{Transport: transport}
  
  	jar, err := cookiejar.New(nil)
  
  	if err != nil {
  		return nil, err
  	}
  
  	u, err := url.Parse(requrl)
  
  	if err != nil {
  		return nil, err
  	}
  
  	codec := clientCodec{
  		url:        u,
  		httpClient: httpClient,
  		close:      make(chan uint64),
  		ready:      make(chan uint64),
  		responses:  make(map[uint64]*http.Response),
  		cookies:    jar,
  	}
  
  	return &Client{rpc.NewClientWithCodec(&codec)}, nil
  }
docs: // NewClient returns instance of rpc.Client object, that is used to send request to xmlrpc service.