class="token keyword">abstract </span><span class="token keyword"></span><span class="token keyword">fun </span><span class="token operator">&lt;</span><span class="token keyword"></span><a href="observe.html">D</a><span class="token operator"> : </span><a href="../../com.grarcht.shuttle.framework.visibility/-shuttle-visibility-data/index.html">ShuttleVisibilityData</a><span class="token operator">&gt; </span><a href="observe.html"><span class="token function">observe</span></a><span class="token punctuatio