title: Property 'pipe' does not exist on type 'OperatorFunction<unknown, [unknown, boolean, any]>
body: <p>Using Angular 9 I need to check a condition based on two methods that returns two observables:</p>
  <pre><code>    return zip(this.authService.isSignedIn(), this.authService.getRole()).pipe(
        map(([isSignedIn, role]: [boolean, string]) =&gt; isSignedIn &amp;&amp; role &amp;&amp; role.toLowerCase() === 'admin')
      );
  </code></pre>
  <p>But I get the error:</p>
  <pre><code> Property 'pipe' does not exist on type 'OperatorFunction&lt;unknown, [unknown, boolean, any]&gt;
  </code></pre>
  <p>What am I missing?</p>