rror.html">[...]</a>
                  
</dd>
        <dt id="then" class="callable">
          <span class="name"><a href="dart-async/Future/then.html">then</a></span><span class="signature">&lt;<wbr><span class="type-parameter">R</span>&gt;</span><span class="signature">(<wbr><span class="parameter" id="then-param-onValue"><span class="type-annotation"><a href="dart-async/FutureOr-class.html">FutureOr</a><span class="signature">&lt;<wbr><span class="type-parameter">R</span>&gt;</span></span> <span class="