_at</span><span class="special">(</span><span class="identifier">key</span><span class="special">)</span></code>, that
        mimics the standard <code class="computeroutput"><span class="identifier">at</span><span class="special">(</span><span class="identifier">key</span><span class="special">)</span></code> function
        but returned the associated information instead of the data.
      </p>
<p>
</p>
<pre class="programlisting"><span class="comment">// Print the new abstract</span>
<span class="ident