Dictionary: Revert/remove setdefault
<p>I currently have an object passed to my callback which is a dictionary and which I have to return.</p>

<p>The invoker called <code>obj.setdefault("Server", "Something")</code> on the dictionary so that it has a default value even if the key/value pair does not exist.</p>

<p>How can I revert/remove that <code>setdefault</code> (remove the default value)? I mean I simply don't want that key/value pair in the dict and it seems that it doesn't have complications if the key doesn't exit, but it is always added because of the default.</p>