code: public static <S, T, A, B> Lens<S, T, Maybe<A>, B> liftA(Lens<S, T, A, B> lens) {
          return lens.mapA(Maybe::just);
      }
docs: Given a lens, lift <code>A</code> into {@link Maybe}.
  
  @param lens the lens
  @param <S>  the type of the "larger" value for reading
  @param <T>  the type of the "larger" value for putting
  @param <A>  the type of the "smaller" value that is read
  @param <B>  the type of the "smaller" update value
  @return the lens with A lifted