// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

/// @assertion factory StreamTransformer(StreamSubscription<T>
///   transformer(Stream<S> stream, bool cancelOnError))
/// Creates a StreamTransformer.
///
/// The returned instance takes responsibility of implementing (bind). When
/// the user invokes bind it returns a new "bound" stream. Only when the user
/// starts listening to the bound stream, the listen method invokes the given
/// closure transformer.
///
/// @description Checks that returned instance implements bind.
/// @author ilya

import "dart:async";

main() {
  StreamTransformer tr = new StreamTransformer((stream, cancelOnError) {});
  tr.bind;
}