 return type for <a href="dart-ui/PluginUtilities/getCallbackHandle.html">PluginUtilities.getCallbackHandle</a>.</p>
    </section>
    

    <section class="summary offset-anchor" id="constructors">
      <h2>Constructors</h2>

      <dl class="constructor-summary-list">
        <dt id="CallbackHandle.fromRawHandle" class="callable">
          <span class="name"><a href="dart-ui/CallbackHandle/CallbackHandle.fromRawHandle.html">CallbackHandle.fromRawHandle</a></span><span class="signature">(<span class="pa