[PublicAPI] public static LazyVal <Future <B> > lazyMapT <A, B>(
this LazyVal <Future <A> > m, Fn <A, B> mapper
) => m.lazyMap(_ => _.map(mapper));
public static LazyVal <Option <B> > lazyFlatMapT <A, B>(
this LazyVal <Option <A> > m, Fn <A, Option <B> > mapper
) => m.lazyMap(_ => _.flatMap(mapper));
