ass="property">
          <span class="name"><a href="dart-collection/DoubleLinkedQueue/first.html">first</a></span>
          <span class="signature">&#8594; E</span>
        </dt>
        <dd>
          Returns the first element. <a href="dart-collection/DoubleLinkedQueue/first.html">[...]</a>
          <div class="features">read-only</div>
</dd>
        <dt id="isEmpty" class="property">
          <span class="name"><a href="dart-collection/DoubleLinkedQueue/isEmpty.html">isEmpty</a></span>
          <sp