showSnackBar function

Implementation

ScaffoldFeatureController<SnackBar, SnackBarClosedReason>? showSnackBar(
    SnackBar snackBar) {
  assert(FlExtended().scaffoldMessengerKey.currentState != null,
      'Set FlExtended().scaffoldMessengerKey to the MaterialApp');
  return FlExtended().scaffoldMessengerKey.currentState?.showSnackBar(snackBar);
}