title: Error: 'AppRoutingModule' module can't import itself
body: <p>Any help or hint would be greatly appreciated it!!
  I am following angular documentation on routing: <a href="https://angular.io/guide/router" rel="nofollow noreferrer">https://angular.io/guide/router</a>
  I am at end of milestone 2: routing module.</p>
  
  <p>This is my angular-router-sample\src\app\app-routing.module.ts:</p>
  
  <pre><code>                import { NgModule } from '@angular/core';
              import { RouterModule, Routes } from '@angular/router';
  
              import { CrisisListComponent } from './crisis-list/crisis-list.component';
              import { HeroListComponent } from './hero-list/hero-list.component';
              import { PageNotFoundComponent } from './page-not-found/page-not-found.component';
  
  
  
              const appRoutes: Routes = [
                { path: 'crisis-center', component: CrisisListComponent },
                { path: 'heroes', component: HeroListComponent },
                { path: '', redirectTo: '/heroes', pathMatch: 'full' },
                { path: '**', component: PageNotFoundComponent}
              ];
  
              @NgModule({
                declarations: [],
                imports: [
                  RouterModule.forRoot(
                    appRoutes,
                    { enableTracing: true } // &lt;--debugging purposes only
                  ),
                  AppRoutingModule
                ],
                exports: [
                  RouterModule
                ]
              })
              export class AppRoutingModule { }
  </code></pre>
  
  <p>This is my angular-router-sample\src\app\app.module.ts:</p>
  
  <pre><code>                import { NgModule } from '@angular/core';
              import { BrowserModule } from '@angular/platform-browser';
              import { FormsModule } from '@angular/forms';
  
              import { AppComponent } from './app.component';
              import { AppRoutingModule } from './app-routing.module';
  
  
  
              import { CrisisListComponent } from './crisis-list/crisis-list.component';
              import { HeroListComponent } from './hero-list/hero-list.component';
              import { PageNotFoundComponent } from './page-not-found/page-not-found.component';
  
  
              @NgModule({
                declarations: [
                  AppComponent,
                  CrisisListComponent,
                  HeroListComponent,
                  PageNotFoundComponent
                ],
                imports: [
                  BrowserModule,
                  FormsModule,
                  AppRoutingModule,
                //  AppRoutingModule
  
  
                ],
                providers: [],
                bootstrap: [AppComponent]
              })
              export class AppModule { }
  </code></pre>
  
  <p>This is my console log error:</p>
  
  <p><a href="https://i.stack.imgur.com/ptoRh.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ptoRh.jpg" alt="-"></a></p>