title: Decyphering some cryptic legacy JavaScript
body: <p>Quick question (I think).  Given this piece of code:</p>
  
  <pre><code>SomeObject._gaCallbackStack.each( function(callback)
  {
      if ($type(callback) == 'function') callback();
  });
  </code></pre>
  
  <p>What exactly is going on here?  </p>
  
  <p>Is the code calling a function named "callback()" for each function stored in the Callback Stack?  Or is it calling each function in the Callback Stack by appending "()" to the end of the variable name?</p>
  
  <p>Thanks for the help!</p>