public static IObserver <T> Roll <T>(this IObserverF <IObserver <T>, T> node)
{
return(new Observer <T>(() => node));
}
public static IObserverF <B, T> Fmap <A, B, T>(this IObserverF <A, T> node, Func <A, B> convert)
{
return(new ObserverF <B, T>(
stopF: () => node.Stop(),
sendF: message => convert(node.Send(message))));
}