code: function doQuery(options) {
              return models.Subscriber.getByEmail(options.data.subscribers[0].email)
                  .then((subscriber) => {
                      if (subscriber && options.context.external) {
                          // we don't expose this information
                          return Promise.resolve(subscriber);
                      } else if (subscriber) {
                          return Promise.reject(new common.errors.ValidationError({message: common.i18n.t('errors.api.subscribers.subscriberAlreadyExists')}));
                      }
  
                      return models.Subscriber.add(options.data.subscribers[0], _.omit(options, ['data'])).catch((error) => {
                          if (error.code && error.message.toLowerCase().indexOf('unique') !== -1) {
                              return Promise.reject(new common.errors.ValidationError({message: common.i18n.t('errors.api.subscribers.subscriberAlreadyExists')}));
                          }
  
                          return Promise.reject(error);
                      });
                  })
                  .then((model) => {
                      return {
                          subscribers: [model.toJSON(options)]
                      };
                  });
          }
docs: ### Model Query
  Make the call to the Model layer
  @param {Object} options
  @returns {Object} options