code: public static <A> Maybe<A> fromOptional(Optional<? extends A> optional) {
          return optional.map(Maybe::<A>just).orElse(Maybe.nothing());
      }
docs: Convenience static factory method for creating a {@link Maybe} from an {@link Optional}.
  
  @param optional the optional
  @param <A>      the optional parameter type
  @return the equivalent Maybe instance