             Converts each element to a <code class="prettyprint lang-dart">String</code> and concatenates the strings.
              </dd>
              <dt id="lastIndexOf" class="callable">
                  <span class="name ">lastIndexOf</span><span class="signature">(<wbr><span class="parameter" id="lastIndexOf-param-element"><span class="type-annotation">Object</span> <span class="parameter-name">element</span></span>, [<span class="parameter" id="lastIndexOf-param-startIndex"><span class="type-annot