           <span class="returntype parameter">&#8594; <a href="dart-core/Duration-class.html">Duration</a></span>
          </span>
                  </dt>
        <dd>
          Adds this Duration and <code>other</code> and
returns the sum as a new Duration object.
                  
</dd>
        <dt id="operator -" class="callable">
          <span class="name"><a href="dart-core/Duration/operator_minus.html">operator -</a></span><span class="signature">(<wbr><span class="parameter" id="--param-other"><s