replaceStickerInSet(userId, name, oldSticker, form = {}) {
    form.user_id = userId;
    form.name = name;
    form.old_sticker = oldSticker;
    return this._request('deleteStickerFromSet', { form });
  }
Use this method to replace an existing sticker in a sticker set with a new one

@param {Number} user_id User identifier of the sticker set owner
@param {String} name Sticker set name
@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#replacestickerinset
@todo Add tests for this method!