of a structure as optional.">@:optional</span><span class="label label-optional">optional</span><a href="#accelerationIncludingGravity"><span class="identifier">accelerationIncludingGravity</span></a>:<a class="type" title="Null - Null&amp;lt;T&amp;gt; is a wrapper that can be used to make the basic types Int, Float and Bool nullable on static targets." href="../../Null.html">Null</a>&lt;<a class="type" title="js.html.DeviceAccelerationInit" href="../../js/html/DeviceAccelerationInit.html">DeviceAcceleratio