Use this method to upload a .png file with a sticker for later use in createNewStickerSet and addStickerToSet
        methods (can be used multiple times). Returns the uploaded File on success.
        :param user_id:
        :param png_sticker:
        :return:

def upload_sticker_file(self, user_id, png_sticker):
        """
        Use this method to upload a .png file with a sticker for later use in createNewStickerSet and addStickerToSet
        methods (can be used multiple times). Returns the uploaded File on success.
        :param user_id:
        :param png_sticker:
        :return:
        """
        result = apihelper.upload_sticker_file(self.token, user_id, png_sticker)
        return types.File.de_json(result)