sendGenericTemplate(recipientId, elements, options) {
    const payload = {
      template_type: 'generic',
      elements
    };
    options && options.imageAspectRatio && (payload.image_aspect_ratio = options.imageAspectRatio) && (delete options.imageAspectRatio);
    return this.sendTemplate(recipientId, payload, options);
  }
@param {Recipient|String} recipientId
@param {Array.<Element>} elements
@param {SendMessageOptions} [options]