Python newbie: What does this code do?
<p>This is a snippet from Google AppEngine tutorial.</p>

<pre><code>application = webapp.WSGIApplication([('/', MainPage)], debug=True)
</code></pre>

<p>I'm not quite sure what <strong><code>debug=True</code></strong> does inside the constructor call. 
Does it create a local variable with name <code>debug</code>, assign <code>True</code> to it, and pass it to constructor, or is this a way to set a class instance member variable's value in constructor?</p>
