public static Maybe <K> SelectMany <T, K>(this Maybe <T> maybe, Func <T, Maybe <K> > selector)
{
return(maybe.Bind(selector));
}
public static async Task <Maybe <K> > Bind <T, K>(this Task <Maybe <T> > maybeTask, Func <T, Task <Maybe <K> > > selector)
{
Maybe <T> maybe = await maybeTask.DefaultAwait();
return(await maybe.Bind(selector).DefaultAwait());
}