    static function clear(bool $debugPng = false)
    {
        foreach (self::$_cache as $file) {
            if ($file === self::$broken_image) {
                continue;
            }
            if ($debugPng) {
                print "[clear unlink $file]";
            }
            if (file_exists($file)) {
                unlink($file);
            }
        }

        foreach (self::$tempImages as $versions) {
            foreach ($versions as $file) {
                if ($file === self::$broken_image) {
                    continue;
                }
                if ($debugPng) {
                    print "[unlink temp image $file]";
                }
                if (file_exists($file)) {
                    unlink($file);
                }
            }
        }

        self::$_cache = [];
        self::$tempImages = [];
    }
The software allows user input to control or influence paths or file names that are used in filesystem operations.