title: Use angular async pipe with BehaviourSubject/ReplaySubject and auditTime/debounceTime
body: <p>I am trying to subscribe to a BehaviourSubject/ReplaySubject with the angular async pipe. 
  Also i have to use auditTime or debounceTime operator to throw away some values. </p>
  
  <p>Here's an example (i used Angular CLI version 7.3.0 and changed app.component only): </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>import {Component, OnInit} from '@angular/core';
  import {Observable, ReplaySubject, Subject} from 'rxjs';
  import {auditTime, tap} from 'rxjs/operators';
  
  @Component({
    selector: 'app-root',
    template: `{{value$ | async}}`,
    styleUrls: ['./app.component.less']
  })
  export class AppComponent implements OnInit {
  
    private readonly subjectWithState: Subject&lt;number&gt;;
  
    constructor() {
      this.subjectWithState = new ReplaySubject(1);
    }
  
    ngOnInit(): void {
      this.subjectWithState.next(42);
    }
  
    get value$(): Observable&lt;number&gt; {
      return this.subjectWithState.asObservable()
        .pipe(
          tap(value =&gt; console.log(value)),
          auditTime(1000),
        );
    }
  }</code></pre>
  </div>
  </div>
  </p>
  
  <p>The problem is the subject don't stop emitting the (single) value and i don't get any output (see console logs).
  Everything works as expected with a simple Subject or without <em>auditTime(1000)</em>.</p>
  
  <p>I can't find anything which would explain this behavior. How can i use the auditTime or debounceTime operator with async pipe and BehaviourSubject or ReplaySubject?</p>