title: How to use rxjs limit click button once in 2s ？
body: <p>For click button once in 2 seconds, what should I do? Rxjs has many operators like throttleTime.But the grammar is :</p>
  
  <pre><code>Rx.Observable.fromEvent(button, 'click')
    .throttleTime(1000)
    .scan(count =&gt; count + 1, 0)
    .subscribe(count =&gt; console.log(`Clicked ${count} times`));
  </code></pre>
  
  <p>I use angular and Rxjs.The grammar is :</p>
  
  <pre><code> // html
  &lt;button (click) = "clickMe()"&gt;
  
  // ts
  clickMe(){
   alert('yes!!!');
  }
  </code></pre>