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// Copyright (c) 2015, 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.
import 'dart:async';
import '../typed/stream_subscription.dart';
/// Simple delegating wrapper around a [StreamSubscription].
/// Subclasses can override individual methods.
class DelegatingStreamSubscription<T> implements StreamSubscription<T> {
final StreamSubscription<T> _source;
/// Create delegating subscription forwarding calls to [sourceSubscription].
DelegatingStreamSubscription(StreamSubscription<T> sourceSubscription)
: _source = sourceSubscription;
/// Creates a wrapper which throws if [subscription]'s events aren't instances
/// of `T`.
/// This soundly converts a [StreamSubscription] to a `StreamSubscription<T>`,
/// regardless of its original generic type, by asserting that its events are
/// instances of `T` whenever they're provided. If they're not, the
/// subscription throws a [CastError].
static StreamSubscription<T> typed<T>(StreamSubscription subscription) =>
subscription is StreamSubscription<T>
? subscription
: new TypeSafeStreamSubscription<T>(subscription);
void onData(void handleData(T data)) {
void onError(Function handleError) {
void onDone(void handleDone()) {
void pause([Future resumeFuture]) {
void resume() {
Future cancel() => _source.cancel();
Future<E> asFuture<E>([E futureValue]) => _source.asFuture(futureValue);
bool get isPaused => _source.isPaused;