anchor.diff: +import 'dart:html' show MouseEvent;
  +
   import "package:angular2/core.dart" show Directive;
   import "package:angular2/platform/common.dart" show Location;
   
  
positive.code:   "routeParams: routerLink",
    "target: target"
  ], host: const {
    "(click)": "onClick(\$event.button, \$event.ctrlKey, \$event.metaKey)",
    "[attr.href]": "visibleHref",
    "[class.router-link-active]": "isRouteActive"
  })
  
negative.code:     this._updateLink();
    }
  
    void onClick(MouseEvent event) {
      // If any "open in new window" modifier is present, use default browser
      // behavior
      if (event.button != 0 || event.ctrlKey || event.metaKey) {
        return;
      }
  
      // If target is present and not _self, use default browser behavior
      if (this.target is String && this.target != "_self") {
        return;
      }
  
      this._router.navigateByInstruction(this._navigationInstruction);
      event.preventDefault();
    }
  }
  