widgets/InheritedWidget-class.html">InheritedWidget</a> referenced by this widget changes). This
method can potentially be called in every frame and should not have any side
effects beyond building a widget.</p>
<p>The framework replaces the subtree below this widget with the widget
returned by this method, either by updating the existing subtree or by
removing the subtree and inflating a new subtree, depending on whether the
widget returned by this method can update the root of the existing
subtree, as det