Removes the current SnackBar (if any) immediately.
The removed snack bar does not run its normal exit animation. If there are any queued snack bars, they begin their entrance animation immediately.
Source
void removeCurrentSnackBar({ SnackBarClosedReason reason: SnackBarClosedReason.remove }) {
assert(reason != null);
if (_snackBars.isEmpty)
return;
final Completer<SnackBarClosedReason> completer = _snackBars.first._completer;
if (!completer.isCompleted)
completer.complete(reason);
_snackBarTimer?.cancel();
_snackBarTimer = null;
_snackBarController.value = 0.0;
}