public static function getInstance(): MimeType
    {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }
public static function getInstance(): MimeType
    {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }
Returns the singleton instance.

@return MimeType