setStickerKeywords(sticker, form = {}) {
    form.sticker = sticker;
    if (form.keywords) {
      form.keywords = stringify(form.keywords);
    }
    return this._request('setStickerKeywords', { form });
  }
Use this method to change the list of emoji assigned to a `regular` or `custom emoji` sticker.

The sticker must belong to a sticker set created by the bot.

@param {String} sticker File identifier of the sticker
@param {Object} [options] Additional Telegram query options
@return {Promise} True on success
@see https://core.telegram.org/bots/api#setstickerkeywords