empty-route.ts

{
        path: 'refresh' // See `AppComponent.watchForRefresh()`
      },

// ... 

this._router.events
        .pipe(filter(e => e instanceof NavigationEnd))
        .subscribe((e: NavigationEnd) => {
          const current = e.urlAfterRedirects.substr(1);

          if (current === 'refresh') {
            this._location.back();
          }
        })

// ...