DataClass.java

public class Coordinates {
    public int x;
    public int y;

    public Coordinates(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

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public class Child {
    private int age;

    public Child(int age) {
        this.age = age;
    }

    public int getAge() {
        return age;
    }

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