</span><span class="p">:</span> <span class="kc">nil</span><span class="p">)</span>

<span class="kd">public</span> <span class="k">override</span> <span class="kd">func</span> <span class="nf">observeValue</span><span class="p">(</span><span class="n">forKeyPath</span> <span class="nv">keyPath</span><span class="p">:</span> <span class="kt">String</span><span class="p">?,</span> <span class="n">of</span> <span class="nv">object</span><span class="p">:</span> <span class="kt">Any</span><span class="p">?,</s