docs: function sendBroadcast (message_creative_id, custom_label_id) {
    return new Promise (async (resolve, reject) => {
      if (!message_creative_id) {
        reject('Valid message_creative_id required');      
      }
  
      let options = {
        'message_creative_id': message_creative_id
      };    
  
      if (custom_label_id) options.custom_label_id = custom_label_id;
      
      try {
        let response = await this.callBroadcastApi(options);
        resolve(response);
      } catch (e) {
        reject(e);
      }    
    });
  }