/code> appears in the collection <em>before</em> <code>Y</code>. The
 collection's sorting is otherwise arbitrary. In other words, subclasses come before their superclasses.

 <p>
 For example:

 <p>
 Given <code>class B</code>, <code>class A extends B</code> and <code>class Q</code>, two possible orders are;
 <ol>
 <li><code>{A, B, Q}</code>
 <li><code>{Q, A, B}</code>
 </ol>

 <p>
 The only requirement here is that <code>A</code> appears before <code>B</code>, since <code>A</code> is a subclass of
 <code>