docs: function startBroadcastReachEstimation (custom_label_id) {
    return new Promise (async (resolve, reject) => {
      let options = {
        'custom_label_id': custom_label_id || true
      };    
      try {
        let response = await this.callBroadcastApi(options);
        resolve(response);
      } catch (e) {
        reject(e);
      }
    });
  }