Debounced restartable which can help you implement the right search behavior, for example.

debounced_restartable.dart

class DebouncedRestartableTransformer extends StreamTransformerBase<int, int> {
  @override
  Stream<int> bind(Stream<int> stream) {
    return stream.debounce(const Duration(seconds: 1)).switchMap(Stream.value);
  }
}