"name"><a href="dart-async/ZoneSpecification/registerCallback.html">registerCallback</a></span>
          <span class="signature">&#8594; <a href="dart-async/RegisterCallbackHandler.html">RegisterCallbackHandler</a><span class="signature">&lt;R&gt;</span></span>
        </dt>
        <dd>
          
          <div class="features">read-only</div>
</dd>
        <dt id="registerUnaryCallback" class="property">
          <span class="name"><a href="dart-async/ZoneSpecification/registerUnaryCallback.html">regis