listenWhen property

Function to determine if the listener should be called when state changes.

If provided, this function is called with the previous and current state. Return true to call the listener, false to skip it.

Example:

NotifierListener<CounterNotifier, int>(
  listenWhen: (previous, current) => current > previous, // Only listen for increases
  listener: (state) => print('Count increased to: $state'),
  child: MyWidget(),
)