Simple methods from Rx made using Observable.Create<T>()

SimpleObservableCreate.cs

public static class RxExamples
{
    // Equal to Observable.Empty<T>()
    public static IObservable<T> Empty<T>()
    {
        return Observable.Create<T>(observer =>
        {
            observer.OnCompleted();
            return Disposable.Empty;
        });
    }

    // Equal to Observable.Return<T>(/* T value */)
    public static IObservable<T> Return<T>(T value)
    {
        return Observable.Create<T>(observer =>
        {
            observer.OnNext(value);
            observer.OnCompleted();
            return Disposable.Empty;
        });
    }

    // Equal to Observable.Never<T>()
    public static IObservable<T> Never<T>(T value)
    {
        return Observable.Create<T>(observer => Disposable.Empty);
    }

    // Equal to Observable.Throw<T>(new Exception());
    public static IObservable<T> Throw<T>(Exception exception)
    {
        return Observable.Create<T>(observer =>
        {
            observer.OnError(exception);
            return Disposable.Empty;
        });
    }
}