title: Understanding complex chaining in transition.js
body: <p>hey guys i am new to JS and Jquery in general and i was just going through the source of transition.js and came across the following code : </p>
  
  <pre><code>if ($(e.target).is(this)) return e.handleObj.handler.apply(this, arguments)
  </code></pre>
  
  <p>now i understand how the return statement works , i also understand objects in JS(well not entirely , but yeah i get the idea). now i also understand how apply works in js . but still the below line : </p>
  
  <pre><code>return e.handleObj.handler.apply(this, arguments)
  </code></pre>
  
  <p>makes very little practical sense to me . </p>
  
  <p>can somebody really break it down and explain it to me ?? </p>
  
  <p><code>handleObj</code> - i don't see that anywhere in the plugin ? where is that coming from , its very difficult to understand whats going on on that line . </p>
  
  <p>that perticular line can be found on <a href="https://github.com/twbs/bootstrap/blob/master/js/transition.js#L54" rel="nofollow">git</a> too. </p>
  
  <p>Thank you. </p>