GetAllMenUSA.java

private static List<Person> getAllMenUSA(List<Person> persons)
{
  List<Person> menUSA = new ArrayList<>();
  for(Person person : persons)
  {
    if(person.getGender() == Gender.MALE && person.getCitizenship() == Citizenship.USA)
    {
      menUSA.add(person);
    }
  }
  return menUSA;
}