SAP 电商云 Spartacus UI Checkout 页面的三个 page guards

if (guards.length) {
      const canActivateObservables = guards.map((guardClass) => {
        const guard = this.injector.get<CanActivate>(guardClass, null);
        if (isCanActivate(guard)) {
          return wrapIntoObservable(guard.canActivate(route, state)).pipe(
            first()
          );
        } else {
          throw new Error('Invalid CanActivate guard in cmsMapping');
        }
      });