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

        return $this->addUsingAlias(SkillVersionTableMap::COL_IS_MULTIPLE, $isMultiple, $comparison);
    }