Returns Category object by its id.

        :param str cid:
        :rtype: Category
        :return: category object

def get_category_by_id(self, cid):
        """Returns Category object by its id.

        :param str cid:
        :rtype: Category
        :return: category object
        """
        self._cache_init()
        return self._cache_get_entry(self.CACHE_NAME_IDS, cid)