title: Get function associated with setTimeout or setInterval
body: <p>Let's assume that I have the timeout ID returned from <code>setTimeout</code> or <code>setInterval</code>.</p>
  
  <p>Can I get, in some way, the original function or code, associated with it?</p>
  
  <p>Something like this:</p>
  
  <pre><code>var timer_id = setTimeout(function() {
      console.log('Hello Stackoverflowers!');
  }, 100000);
  
  var fn = timer_id.get_function(); // desired method
  fn(); // output: 'Hello Stackoverflowers!'
  </code></pre>