 class="parameter" id="then-param-onValue"><span class="type-annotation">dynamic</span> <span class="parameter-name">onValue</span>(<span class="parameter" id="onValue-param-value"><span class="type-annotation">T</span> <span class="parameter-name">value</span></span>), {</span> <span class="parameter" id="then-param-onError"><span class="type-annotation"><a href="dart-core/Function-class.html">Function</a></span> <span class="parameter-name">onError</span></span> })
    </section>
    <section class="desc 