getState method
Retrieves the shared state for a specific type.
Parameters:
type: The identifier for the state type to retrieve
Returns a Future that completes with the state data as a Map, or null if no state exists for the given type.
This method should return consistent state across all displays.
Implementation
Future<Map<String, dynamic>?> getState(String type) {
throw UnimplementedError('getState() has not been implemented.');
}