l">Parameters:</span></dt>
<dd><code>event</code> - the event object</dd>
<dt><span class="returnLabel">Returns:</span></dt>
<dd>a <a href="https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CompletionStage.html?is-external=true" title="class or interface in java.util.concurrent"><code>CompletionStage</code></a> allowing further pipeline composition on the asynchronous operation.
         Default asynchronous execution facility is container specific.
         If any observer notified by this eve