 class="nf">methodThatTakesCompletionBlock</span><span class="p">(</span><span class="nv">completion</span><span class="p">:</span> <span class="o">.</span><span class="n">any</span><span class="p">,</span> <span class="nv">perform</span><span class="p">:</span> <span class="p">{</span> <span class="n">completion</span> <span class="k">in</span>
    <span class="nf">completion</span><span class="p">(</span><span class="kc">true</span><span class="p">,</span><span class="kc">nil</span><span class="p">)</span