// App zu einem Angular-Modul zusammenfassen
 import { NgModule } from '@angular/core';
 import { BrowserModule } from '@angular/platform-browser';
 import { FormsModule } from '@angular/forms';
 import { AppComponent } from './app.component';
 import { StackService } from './stack.service';

 @NgModule({
   imports:      [ BrowserModule, FormsModule],
   declarations: [ AppComponent ],
   bootstrap:    [ AppComponent ],
   providers:    [ StackService]
 })
 export class AppModule { }