title: Angular 6 throttleTime doesnt exist in Rx Js
body: <p>I am using <code>angular/cli": "~6.1.5</code>  and <code>rxjs": "^6.0.0</code>
  As i new to Angular 6 i started learning from official document</p>
  
  <p><a href="http://reactivex.io/rxjs/class/es6/Observable.js~Observable.html" rel="nofollow noreferrer">http://reactivex.io/rxjs/class/es6/Observable.js~Observable.html</a></p>
  
  <p>code is below</p>
  
  <pre><code>var clicks = Rx.Observable.fromEvent(document, 'click');
  var result = clicks.throttleTime(1000);
  result.subscribe(x =&gt; console.log(x));
  </code></pre>
  
  <p>Same above code i tried in angular 6 </p>
  
  <pre><code>fromEvent(mybuttonId, 'click')
        .subscribe((event) =&gt; console.log('clicked'));
  </code></pre>
  
  <p>But if i add .throttleTime(1000) to from event then it will throw error</p>
  
  <blockquote>
    <p>Property 'throttleTime' does not exist on type 'Observable</p>
  </blockquote>
  
  <p>'`.</p>
  
  <p>if i try to add Observable.fromEvent then that method doesn't exist </p>
  
  <p>I have imported Rx js as </p>
  
  <pre><code>import {Observable, fromEvent, from, of} from 'rxjs';
  import {throttleTime} from 'rxjs/operators';
  </code></pre>
  
  <p>Can any one help me where i can find exact document for latest version.</p>
  
  <p>Thanks</p>