namespace System.Reactive { public static class Notification { public static Notification<T> CreateOnNext<[System.Runtime.CompilerServices.Nullable(2)] T>(T value); public static Notification<T> CreateOnError<[System.Runtime.CompilerServices.Nullable(2)] T>(Exception error); public static Notification<T> CreateOnCompleted<[System.Runtime.CompilerServices.Nullable(2)] T>(); } }