private function isOrderByInTopNSubquery($query, $currentPosition)
    {
        // Grab query text on the same nesting level as the ORDER BY clause we're examining.
        $subQueryBuffer = '';
        $parenCount     = 0;

        // If $parenCount goes negative, we've exited the subquery we're examining.
        // If $currentPosition goes negative, we've reached the beginning of the query.
        while ($parenCount >= 0 && $currentPosition >= 0) {
            if ($query[$currentPosition] === '(') {
                $parenCount--;
            } elseif ($query[$currentPosition] === ')') {
                $parenCount++;
            }

            // Only yank query text on the same nesting level as the ORDER BY clause.
            $subQueryBuffer = ($parenCount === 0 ? $query[$currentPosition] : ' ') . $subQueryBuffer;

            $currentPosition--;
        }

        return (bool) preg_match('/SELECT\s+(DISTINCT\s+)?TOP\s/i', $subQueryBuffer);
    }