changeStream method
Returns a copy of this with stream replaced by change's return
value.
Implementation
@override
StreamChannel<T> changeStream(Stream<T> Function(Stream<T>) change) =>
    StreamChannel.withCloseGuarantee(change(stream), sink);Returns a copy of this with stream replaced by change's return
value.
@override
StreamChannel<T> changeStream(Stream<T> Function(Stream<T>) change) =>
    StreamChannel.withCloseGuarantee(change(stream), sink);