ighlight objective_c"><code><span class="k">@property</span> <span class="p">(</span><span class="n">nonatomic</span><span class="p">,</span> <span class="n">strong</span><span class="p">,</span> <span class="n">nullable</span><span class="p">)</span> <span class="n">NSNumber</span><span class="o">&lt;</span><span class="n"><a href="../Protocols.html#/c:objc(pl)SDLBool">SDLBool</a></span><span class="o">&gt;</span> <span class="o">*</span><span class="n">subscribe</span><span class="p">;</span></code></pre>