anchor.diff:    Future<ComponentRef> attachComponentPortal(ComponentPortal portal) {
       // By default, use the portal host as the origin. If [portal.origin] is set
       // however, then use that.
  -    portal.setAttachedHost(this);
       var viewContainerRef = _viewContainerRef;
       if (portal.origin != null) {
         viewContainerRef = portal.origin;
  
positive.code:     }
      if (portal is ComponentPortal) {
        _attachedPortal = portal;
        return attachComponentPortal(portal);
      } else if (portal is TemplatePortal) {
        _attachedPortal = portal;
        return attachTemplatePortal(portal);
      } else if (portal == null) {
        throw ArgumentError.notNull('portal');
  
negative.code: 
    @override
    Future<Map<String, dynamic>> attachTemplatePortal(TemplatePortal portal) {
      final viewRef = _viewContainerRef.createEmbeddedView(portal.template);
      portal.locals.forEach(viewRef.setLocal);
      setPortalDisposer(_viewContainerRef.clear);
  