title: Throttle method call as we throttle View clicks with RxJava
body: <p>Is there a way to throttle method calls i.e only take the first event within a certain window duration. I have seen examples of RxBinding like</p>
  
  <pre><code>RxView.clicks(mButton)
              .throttleFirst(300, TimeUnit.MILLISECONDS, AndroidSchedulers.mainThread())
              .subscribe(...);
  </code></pre>
  
  <p>How can I do the above to a method ?</p>