private static function getFileLines(string $filePath, int $start, int $length): ?array
    {
        if (($contents = self::getFileContents($filePath)) !== null) {
            $lines = \explode("\n", $contents);

            if ($start < 0) {
                $start = 0;
            }

            return \array_slice($lines, $start, $length, true);
        }
    }