See: https://core.telegram.org/bots/api#uploadstickerfile

def uploadStickerFile(self, user_id, png_sticker):
        """
        See: https://core.telegram.org/bots/api#uploadstickerfile
        """
        p = _strip(locals(), more=['png_sticker'])
        return self._api_request_with_file('uploadStickerFile', _rectify(p), 'png_sticker', png_sticker)