import java.util.List;import java.util.Objects;public class Main {    public static void main(String[] args) {        List<Person> list = List.of(                new Person("Xiao", "Ming", 18),                new Person("Xiao", "Hong", 25),                new Person("Bob", "Smith", 20)        );        boolean exist = list.contains(new Person("Bob", "Smith", 20));        System.out.println(exist ? "测试成功!" : "测试失败!");    }}class Person {    String firstName;    String lastName;    int age;    public Person(String firstName, String lastName, int age) {        this.firstName = firstName;        this.lastName = lastName;        this.age = age;    }    public boolean equals (Object o){        if (o instanceof Person){            Person p = (Person) o;            return Objects.equals(this.firstName,p.firstName)&&Objects.equals(this.lastName,p.lastName)&&(this.age==p.age);        }        return false;    }    }