Код для конвертации Java в Kotlin

Gender.java

enum Gender {
    MALE("m"),
    FEMALE("f");

    String id;

    public static Gender getById(String id) {
        switch(id) {
            case "m": return MALE;
            case "f": return FEMALE;
            default: throw IllegalStateException();
        }
    }
}

House.java

class House {

    private List persons = new ArrayList<Person>();
    private List children = new ArrayList<Person>();
    private List adultWomen = new ArrayList<Person>();
    private List adultMen = new ArrayList<Person>();

    public House() {
        children.add(new Person("Anna"), 2, FEMALE);
        adultMen.add(new Person("Mike"), 45, MALE);
        adultWomen.add(new Person("Maria"), 45, FEMALE);
        children.add(new Person("Boris"), 15, MALE);
        adultMen.add(new Person("Jordan"), 21, MALE);

        persons.addAll(children);
        persons.addAll(adultWomen);
        persons.addAll(adultMen);
    }

    public List<Person> getAdults() {
        List adults = new ArrayList<Person>();
        for (Person p: persons) {
            if (p.getAge() > 18) {
                adults.add(p);
            }
        }

        return adults;
    }

    public void addPerson(Person p) {
        if (p.getAge() > 18) {
            if (p.getGender() == MALE) {
                adultMen.add(p);
            } else {
                adultWomen.add(p);
            }
        } else {
            children.add(p);
        }

        persons.add(p);
    }

    public void sayHelloToPerson(@Nullable Person p) {
        String greet;

        if (p != null) {
          
            if (p.getAge() < 14) {
                greet = "Hello, little " + p.getName();
            } else if (p.getAge() >= 14 && p.getAge() < 18 ) {
                switch(p.getGender()) {
                    case MALE: greet = "Hello boy!";
                    break;
                    case FEMALE: greet = "Hello girl!";
                    break;
                }
            } else {
                switch(p.getGender()) {
                    case MALE: greet = "Hello  man!";
                    break;
                    case FEMALE: greet = "Hello  woman!";
                    break;
                }
            }
        }

        if (greet != null) {
            System.out.print(greet);
        }
    }
}

Person.java

public class Person {
    private final String name;
    private int age;
    private final Gender gender;

    public Person(String name, Gender gender) {
        this(name, 0, gender)
    }

    public Person(String name, int age, Gender gender) {
        this.name = name;
        this.age = age;
        this.gender = gender;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public Gender getGender() {
        return gender;
    }

    public static Person from(Map<String, String> personMap) {
        return Person(personMap.get("name"), 
            personMap.get("age"), 
            Gender.getById(personMap.get("gender"))
            );
    }
}