Добрый день! Подскажите что не так
package com.javarush.task.task20.task2028;
import java.util.List;
public class Solution {
public static void main(String[] args) {
List<String> list = new CustomTree();
for (int i = 1; i < 16; i++) {
list.add(String.valueOf(i));
}
System.out.println("List size is " + list.size());
System.out.println("Expected parent is 3, actual parent is " + ((CustomTree) list).getParent("8"));
System.out.println("Expected parent is null, actual parent is " + ((CustomTree) list).getParent("20"));
list.remove("3");
System.out.println("Expected parent is null, actual parent is " + ((CustomTree) list).getParent("8"));
list.add("16");
System.out.println("Expected parent is 9, actual parent is " + ((CustomTree) list).getParent("16"));
list.remove("4");
list.remove("5");
list.remove("6");
System.out.println("Expected true, actual " + list.add("20"));
System.out.println("Expected parent is 1, actual parent is " + ((CustomTree) list).getParent("20"));
}
}