namespace System.ClientModel.Internal { internal static class StreamExtensions { public static Task WriteAsync(this Stream stream, ReadOnlyMemory<byte> buffer, CancellationToken cancellation = default(CancellationToken)); public static Task WriteAsync(this Stream stream, ReadOnlySequence<byte> buffer, CancellationToken cancellation = default(CancellationToken)); public static Task CopyToAsync(this Stream source, Stream destination, CancellationToken cancellationToken); public static void CopyTo(this Stream source, Stream destination, CancellationToken cancellationToken); } }