UserWorkItem<TState>
using System.Reactive.Disposables;
using System.Runtime.CompilerServices;
namespace System.Reactive.Concurrency
{
    [System.Runtime.CompilerServices.NullableContext(1)]
    [System.Runtime.CompilerServices.Nullable(0)]
    internal sealed class UserWorkItem<[System.Runtime.CompilerServices.Nullable(2)] TState> : IDisposable
    {
        private SingleAssignmentDisposableValue _cancelRunDisposable;
        private SingleAssignmentDisposableValue _cancelQueueDisposable;
        private readonly TState _state;
        private readonly IScheduler _scheduler;
        private readonly Func<IScheduler, TState, IDisposable> _action;
        public IDisposable CancelQueueDisposable {
            set {
                _cancelQueueDisposable.Disposable = value;
            }
        }
        public UserWorkItem(IScheduler scheduler, TState state, Func<IScheduler, TState, IDisposable> action)
        {
            _state = state;
            _action = action;
            _scheduler = scheduler;
        }
        public void Run()
        {
            if (!_cancelRunDisposable.IsDisposed)
                _cancelRunDisposable.Disposable = _action(_scheduler, _state);
        }
        public void Dispose()
        {
            _cancelQueueDisposable.Dispose();
            _cancelRunDisposable.Dispose();
        }
    }
}