GetAllPersonByGenderCitizenshipAge.java

private List<Person> getAllPersonByGenderCitizenshipAge(List<Person> persons, Gender gender, Citizenship citizenship, int age)
{
	List<Person> people = new ArrayList<>();
	for(Person person : persons){
		if(person.getGender() == gender && person.getCitizenship() == citizenship && person.getAge() > age)
		{
			people.add(person);
		}
	}
	return people;
}