<p dir="auto">Open Components &gt; Selection Controls (actually named toggle_controls_demo.dart in the source) and click on any switch at the bottom.</p>
<p dir="auto">All of the switches will expand while the first one is animating.<br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://cloud.githubusercontent.com/assets/11857803/13687447/3493e608-e6d0-11e5-80d2-f841dcaa8a97.png"><img src="https://cloud.githubusercontent.com/assets/11857803/13687447/3493e608-e6d0-11e5-80d2-f841dcaa8a97.png" alt="screen" style="max-width: 100%;"></a></p>
<p dir="auto">e.g. look at the settings page in stocks. Note that it fixes itself if you toggle any switch.</p>