BlocEventStateBuilder(
  bloc: distanceBloc,
  builder: (
  BuildContext context,
      DistanceCalculationState state,
  ) {
  Widget result = Container(
  height: 0.0,
  width: 0.0,
  );

  if (state.isCalculating) {
  Scaffold.of(context).showSnackBar(
  SnackBar(
  content: Text(
  'duration ${state.durationResponse.text} distance ${state.distanceResponse.text}',
  style: Theme.of(context)
      .textTheme
      .subhead
      .copyWith(color: Colors.black54),
  ),
  ),
  );
  }

  return result;
  },
  )