static public function widget($name=null)
	{
	    if ($name = static::findClass($name, 'widget')) {
	        $id = 'widget' . ($name ? '.' . $name : '');
	        if (!static::has($id)) {
	            static::setShared($id, function () use ($name) {
	                if ($name instanceof \Wslim\View\Widget) {
	                    return $name::instance();
	                } else {
	                    return new $name;
	                }
	            });
	        }
	        return static::get($id);
	    }
	    return null;
	}