span class="p">(</span><span class="k">self</span><span class="p">,</span> <span class="nv">forKeyPath</span><span class="p">:</span> <span class="s">"effectiveTheme"</span><span class="p">,</span> <span class="nv">options</span><span class="p">:</span> <span class="kt">NSKeyValueObservingOptions</span><span class="o">.</span><span class="nf">init</span><span class="p">(</span><span class="nv">rawValue</span><span class="p">:</span> <span class="mi">0</span><span class="p">),</span> <span class="nv">context