e given closure when the result of this <code>DownloadResponse</code> is a success, passing the unwrapped
result value as a parameter.</p>

<p>Use the <code>flatMap</code> method with a closure that may throw an error. For example:</p>
<pre class="highlight swift"><code><span class="k">let</span> <span class="nv">possibleData</span><span class="p">:</span> <span class="kt">DownloadResponse</span><span class="o">&lt;</span><span class="kt">Data</span><span class="o">&gt;</span> <span class="o">=</span> <span