giftPremiumSubscription(userId, monthCount, starCount, form = {}) {
    form.user_id = userId;
    form.month_count = monthCount;
    form.star_count = starCount;
    return this._request('giftPremiumSubscription', { form });
  }
Use this method to sends a gift to the given user or channel chat.

@param {Number} userId Unique identifier of the target user who will receive a Telegram Premium subscription.
@param {Number} monthCount Number of months the Telegram Premium subscription will be active for the user; must be one of 3, 6, or 12.
@param {String} starCount Number of Telegram Stars to pay for the Telegram Premium subscription; must be 1000 for 3 months, 1500 for 6 months, and 2500 for 12 months.
@param {Object} [options] Additional Telegram query options.
@return {Promise} On success, returns true.
@see https://core.telegram.org/bots/api#getavailablegifts