private function getQueryClause($query, $clause)
    {
        $queries = $query->getMust();

        if ($clause == self::QUERY_CONDITION_NOT) {
            $queries = $query->getMustNot();
        } elseif ($clause == self::QUERY_CONDITION_SHOULD) {
            $queries = $query->getShould();
        }

        return $queries;
    }