static public function buildParameterValue($operator, $value)
    {
        FilterOperator::isValid($operator, true);

        switch (intval($operator)) {
            case FilterOperator::LIKE:
            case FilterOperator::NOT_LIKE:
                return sprintf('%%%s%%', $value);
            case FilterOperator::START_WITH:
            case FilterOperator::NOT_START_WITH:
                return sprintf('%s%%', $value);
            case FilterOperator::END_WITH:
            case FilterOperator::NOT_END_WITH:
                return sprintf('%%%s', $value);
            default:
                return $value;
        }
    }