# System.IO

``` diff
 namespace System.IO {
     public class MemoryStream : Stream {
-        public override void CopyTo(ReadOnlySpanAction<byte, object> callback, object state, int bufferSize);

-        public override Task CopyToAsync(Func<ReadOnlyMemory<byte>, object, CancellationToken, ValueTask> callback, object state, int bufferSize, CancellationToken cancellationToken);

     }
     public abstract class Stream : MarshalByRefObject, IAsyncDisposable, IDisposable {
-        public virtual void CopyTo(ReadOnlySpanAction<byte, object> callback, object state, int bufferSize);

-        public virtual Task CopyToAsync(Func<ReadOnlyMemory<byte>, object, CancellationToken, ValueTask> callback, object state, int bufferSize, CancellationToken cancellationToken);

     }
     public class UnmanagedMemoryStream : Stream {
-        public override void CopyTo(ReadOnlySpanAction<byte, object> callback, object state, int bufferSize);

     }
 }
```

