docs: function sendCsMessage(csMessage){
    var token = this.instance.getAccessToken();
    var url = 'https://api.WeiXin.qq.com/cgi-bin/message/custom/send?access_token='+token;
    var fiber = fibext();
    hr.post(url, {json: csMessage}, util.processResponse(function(err, body){
      fiber.resume(err, body);
    }));
    return fiber.wait();
  }