ection class="multi-line-signature">
              <span class="returntype"><a href="polymer_app_layout/EventStreamProvider-class.html">EventStreamProvider</a>&lt;<a href="dart-html/AnimationEvent-class.html">AnimationEvent</a>&gt;</span>
              <span class="name ">animationStartEvent</span>              =
              <span class="constant-value">const <a href="polymer_app_layout/EventStreamProvider-class.html">EventStreamProvider</a>&lt;<a href="dart-html/AnimationEvent-class.html">AnimationEvent<