namespace System.Reactive.Concurrency { public interface IScheduler { DateTimeOffset Now { get; } IDisposable Schedule<[System.Runtime.CompilerServices.Nullable(2)] TState>(TState state, Func<IScheduler, TState, IDisposable> action); IDisposable Schedule<[System.Runtime.CompilerServices.Nullable(2)] TState>(TState state, TimeSpan dueTime, Func<IScheduler, TState, IDisposable> action); IDisposable Schedule<[System.Runtime.CompilerServices.Nullable(2)] TState>(TState state, DateTimeOffset dueTime, Func<IScheduler, TState, IDisposable> action); } }