BooleanDisposable
Represents a disposable resource that can be checked for disposal status.
            
                using System.Runtime.CompilerServices;
namespace System.Reactive.Disposables
{
    public sealed class BooleanDisposable : ICancelable, IDisposable
    {
        [System.Runtime.CompilerServices.Nullable(1)]
        internal static readonly BooleanDisposable True = new BooleanDisposable(true);
        private volatile bool _isDisposed;
        public bool IsDisposed => _isDisposed;
        public BooleanDisposable()
        {
        }
        private BooleanDisposable(bool isDisposed)
        {
            _isDisposed = isDisposed;
        }
        public void Dispose()
        {
            _isDisposed = true;
        }
    }
}