span><span class="p">[</span><span class="mf">0</span><span class="p">]</span>
<span class="w">  </span><span class="p">}</span>
</code></pre></div>
</div>
<p>To test this code, we start with the last of these three short files:</p>
<div class="code-sample lang-js" title="upper.js">
<div class="highlight"><pre><span></span><code><span class="kd">class</span><span class="w"> </span><span class="nx">Upper</span><span class="w"> </span><span class="p">{</span>
<span class="w">  </span><span class="kr">construc