         </dt>
            <dd>
              Built-in types and core primitives for a Flutter application. <a href="dart-ui/dart-ui-library.html">[...]</a>
            </dd>            <h3>Core</h3>
              <dt id="dart:async">
                <span class="name"><a href="dart-async/dart-async-library.html">dart:async</a></span>               
              </dt>
              <dd>
                Support for asynchronous programming,
with classes such as Future and Stream. <a href="dart-async/dart-as