state property
      
      set
      state
      (SmsMessageState state) 
      
    
    
    
Implementation
set state(SmsMessageState state) {
  if (_state != state) {
    _state = state;
    _stateStreamController.add(state);
  }
}set state(SmsMessageState state) {
  if (_state != state) {
    _state = state;
    _stateStreamController.add(state);
  }
}