I've passed validation of the below task however my Intelij IDE shows me the following error "Ambiguous method call: both 'B.method1()' and 'A.method1()' match". why? I've some more questions about this task: - Why I was able to run it if my IDE shows an error? Does it have something to do with some configuration? - If method1 of class A gets a private modifier, should this method be accessible from an external class? I mean the error is shown because both method1 from class A and class B are visible however one is marked as private since the other as public. 
package com.codegym.task.task20.task2023;

/*
Making the right conclusion

*/

public class Solution {
    public static void main(String[] s) {
        A a = new C();
        a.method2();
    }

    public static class A {
        private void method1() {
            System.out.println("A class, method1"); // 3
        }

        public void method2() {
            System.out.println("A class, method2"); // 2
            method1();
        }
    }

    public static class B extends A {
        public void method1() {
            super.method2();
            System.out.println("B class, method1"); // 4
        }

        public void method2() {
            System.out.println("B class, method2");
        }
    }

    public static class C extends B {
        public void method1() {
            System.out.println("C class, method1");
        }

        public void method2() {
            System.out.println("C class, method2"); // 1
            super.method1();
        }
    }
}