location in the
tree at which this widget is being built. For example, the context
provides the set of inherited widgets for this location in the tree. A
given widget might be built with multiple different <a href="https://api.flutter.dev/flutter/widgets/BuildContext-class.html">BuildContext</a>
arguments over time if the widget is moved around the tree or if the
widget is inserted into the tree in multiple places at once.</p>
<p>The implementation of this method must only depend on:</p>
<ul>
<li>the fields