pkg/front_end/testcases/nnbd_mixed/sink_hierarchy.dart.textual_outline.expect

// @dart = 2.6
abstract class Sink<T> {
  void close();
}

abstract class EventSink<T> implements Sink<T> {
  void close();
}

abstract class StreamConsumer<S> {
  Future close();
}

abstract class StreamSink<S> implements EventSink<S>, StreamConsumer<S> {
  Future close();
}

main() {}