title: Unexpected value '[object Object]' imported by the module 'AppModule'
body: <p>I want to import Pipe Module to my app,</p>
  
  <pre><code>import { NgModule } from '@angular/core';
  import { PipeTransform, Pipe } from '@angular/core';
  
  @Pipe({ name: 'values',  pure: false })
  export class PipeModule implements PipeTransform {
    transform(value: any, args: any[] = null): any {
      return Object.keys(value).map(key =&gt; value[key]);
    }
  
    static forRoot() {
        return {
            ngModule: PipeModule,
            providers: [],
        };
     }
  }
  </code></pre>
  
  <p>this is my pipe module</p>
  
  <p>at my
  <strong>app.module.ts</strong></p>
  
  <pre><code>imports: [
     ...,
      PipeModule.forRoot()
  </code></pre>
  
  <p>I import it like this and I get this error</p>
  
  <pre><code>Unexpected value '[object Object]' imported by the module 'AppModule
  </code></pre>