# System.IO.Pipes ``` diff namespace System.IO.Pipes { public sealed class AnonymousPipeClientStream : PipeStream { + ~AnonymousPipeClientStream(); } public sealed class AnonymousPipeServerStream : PipeStream { + ~AnonymousPipeServerStream(); } public sealed class NamedPipeClientStream : PipeStream { + ~NamedPipeClientStream(); } public sealed class NamedPipeServerStream : PipeStream { + ~NamedPipeServerStream(); } public abstract class PipeStream : Stream { + public override Task FlushAsync(CancellationToken cancellationToken); } } ```