e/bool-class.html">bool</a></span>         
        </dt>
        <dd class="inherited">
          Returns true if there is at least one key/value pair in the map. 
                  <div class="features">read-only, inherited</div>
</dd>
        <dt id="keys" class="property inherited">
          <span class="name"><a href="../dart-collection/MapView/keys.html">keys</a></span>
          <span class="signature">&#8594; <a href="../dart-core/Iterable-class.html">Iterable</a><span class="signature">&lt;<wbr><s