notifyChanges method Null safety
- List<
EmpireStateChanged> events 
Inform the bound EmpireState that the state of the UI needs to be updated.
NOTE: Although you CAN call this method manually, it's usually not required. Updating the value of an EmpireProperty will automatically notify the UI to update itself.
Implementation
void notifyChanges(List<EmpireStateChanged> events) {
  if (_stateController.isClosed) {
    return;
  }
  _stateController.add(events);
}