ances.</dd>
	
	<dt><code><b>subclassof</b>(class, super)</code></dt>
	<dd>Returns true if <code>class</code> is a sub-class of <code>super</code> and false otherwise.</dd>

	<dt><code><b>superclass</b>(class)</code></dt>
	<dd>Returns the super-class of <code>class</code>. If <code>class</code> is not a class of the model or does not define a super class, then it returns <code>nil</code>.</dd>
</dl>

<h3>Example</h3>

<pre>
Circle = oo.class()
function Circle:diameter()
  return self.radius * 2
end
function 