public synchronized <T> T get(Class<T> cls) {
        Object service = this.registry.get( cls.getName() );
        if (cls.isInstance( service )) {
            return (T) service;
        }
        try {
            return (T) Class.forName( service.getClass().getCanonicalName() ).newInstance();
        } catch (Exception e) {
            throw new RuntimeException( e );
        }
    }