--- parents: - "[[Вопросы для собеседование Java]]" --- ```java public class Train { public static void main() { println(null); } private static void println(Parent o) { System.out.println(o); } private static void println(Child o) { System.out.println(o); } private static void println(Object o) { System.out.println(o); } } class Parent { } class Child extends Parent { } ``` %% null %%