class="w"> </span><span class="nx">Upper</span>
</code></pre></div>
</div>
<div class="code-sample lang-js" title="middle.js">
<div class="highlight"><pre><span></span><code><span class="k">import</span><span class="w"> </span><span class="nx">Upper</span><span class="w"> </span><span class="kr">from</span><span class="w"> </span><span class="s1">&#39;./upper.js&#39;</span>

<span class="kd">class</span><span class="w"> </span><span class="nx">Middle</span><span class="w"> </span><span class="k">extends</sp