er" id="containsKey-param-key"><span class="type-annotation"><a href="dart-core/Object-class.html">Object</a></span> <span class="parameter-name">key</span></span>)
            <span class="returntype parameter">&#8594; <a href="dart-core/bool-class.html">bool</a></span>
          </span>
                  </dt>
        <dd>
          Returns true if this map contains the given <code>key</code>. <a href="dart-collection/MapMixin/containsKey.html">[...]</a>
                  <div class="features">override</d