Reactive Extensions: AnonymousDisposable

When you subscribe to a channel in Retlang, you get an IUnsubscriber back.  The equivalent of this in Rx is just IDisposable.  This makes AnonymousDisposable is a fairly vital class in ReactiveExtensions. I even used it in the last post. It's a pity someone decided to mark it as internal (again).  So here's another implementation of it:

public class AnonymousDisposable : IDisposable
{
    private readonly Action _onDispose;

    public AnonymousDisposable(Action onDispose)
    {
        _onDispose = onDispose;
    }

    public void Dispose()
    {
        _onDispose();
    }
}