валидатор ругается по пункту- вывести созданные объекты на экран

package com.javarush.task.task07.task0724;

/*
Семейная перепись
*/

import org.omg.PortableServer.THREAD_POLICY_ID;

public class Solution {
    public static void main(String[] args) {
        //напишите тут ваш код
        Human grandFather = new Human("Евгений", true, 80);
        Human grandFather2 = new Human("Николай", true, 78);

        Human grandMother = new Human("Анна", false, 70);
        Human grandMother2 = new Human("Евдокия", false, 90);

        Human father = new Human("Анатолий", true, 60, grandFather, grandMother);
        Human mother = new Human("Любовь", false, 63, grandFather2, grandMother2);

        Human sun  = new Human("Виктор", true, 37, father, mother);
        Human daughters  = new Human("Виктория", false, 27, father, mother);
        Human sun2  = new Human("Василий", true, 17, father, mother);

        System.out.println(grandFather);
        System.out.println(grandFather2);

        System.out.println(grandMother);
        System.out.println(grandFather2);

        System.out.println(father);
        System.out.println(mother);

        System.out.println(sun);
        System.out.println(daughters);
        System.out.println(sun2);



    }

    public static class Human {
        //напишите тут ваш код
        String name;
        boolean sex;
        int age;
        Human father;
        Human mother;

        public Human(String name, boolean sex, int age) {
            this.name = name;
            this.sex = sex;
            this.age = age;

        }

        public Human(String name, boolean sex, int age, Human father, Human mother) {
            this.name = name;
            this.sex = sex;
            this.age = age;
            this.father = father;
            this.mother = mother;
        }



        public String toString() {
            String text = "";
            text += "Имя: " + this.name;
            text += ", пол: " + (this.sex ? "мужской" : "женский");
            text += ", возраст: " + this.age;

            if (this.father != null)
                text += ", отец: " + this.father.name;

            if (this.mother != null)
                text += ", мать: " + this.mother.name;

            return text;
        }
    }
}