Java Optional - Good Practice

• orElseThrow: if personService.getAll() returns an Optional, then:
  return personService.getAll().map(converter::toResource).orElseThrow(
         () -> new NoResourceFound(...)
  );
• orElse: if personService.getByLastName() returns an optional:
  return personService.getByLastName(lName).orElse(null);