title: What is a ZoneAwarePromise
body: <p>I am using angular 6. One of the http calls returns a <code>ZoneAwarePromise</code> when I try to convert the <code>Observable</code> into a <code>Promise</code>. Also the then block is not getting called.</p>
  
  <pre><code>const login = this.authService.login(email, password).toPromise()
  login.then(() =&gt; {\* not getting called*\})
  </code></pre>
  
  <p>Can someone explain what is a <code>ZoneAwarePromise</code> ?</p>