In a stateful widget, which method is called when the widget configuration changes?

The 'didUpdateWidget()' method in a stateful widget is called when the widget configuration changes. This method is invoked whenever the framework replaces an old widget with a new one of the same runtime type. Developers can use this method to respond to changes in widget properties and update the widget's internal state accordingly. Understanding the lifecycle methods, such as 'didUpdateWidget()', is crucial for managing stateful widgets effectively in Flutter.