use computed properties as values to create new computed properties.
Let's add a <code>description</code> computed property to the previous example,
and use the existing <code>fullName</code> property and add in some other properties:</p>
<pre class="language-javascript line-numbers"><code class="javascript language-javascript">Person <span class="token operator">=</span> Ember<span class="token punctuation">.</span>Object<span class="token punctuation">.</span><span class="token function">extend</span><spa