public static function isOutOfDate(PhingFile $src, PhingFile $target, $granularity)
    {
        if (!$src->exists()) {
            return false;
        }
        if (!$target->exists()) {
            return true;
        }
        if (($src->lastModified() - $granularity) > $target->lastModified()) {
            return true;
        }

        return false;
    }