public function filterByManaged($managed = null, $comparison = null)
    {
        if (is_string($managed)) {
            $managed = in_array(strtolower($managed), array('false', 'off', '-', 'no', 'n', '0', '')) ? false : true;
        }

        return $this->addUsingAlias(ReferenceTableMap::COL_MANAGED, $managed, $comparison);
    }