title: Find which event called the listener in Node.js
body: <p>There is only one listener attached to several events like this:</p>
  
  <pre><code>// emitter is an instance of events.EventEmitter..    
  emitter.on('event1', listener);    
  emitter.on('event2', listener);    
  emitter.on('event3', listener);    
  emitter.on('event4', listener);    
  function listener() { 
     // I need to find which event was emitted and as a result, this listener was called.    
  }
  </code></pre>
  
  <p>Please note that <code>arguments.callee.caller.name</code> won't work in Node, since <code>events.EventEmitter.on</code> method calls an anonymous function and therefore the <code>callee.caller</code> has no name!</p>
  
  <p>Thanks!</p>