错误“类型为‘WithXXX’的类型中缺少属性”

public interface Person {
    String getName();
    int getAge();
}

public class Student implements Person {
    private String name;

    public String getName() {
        return name;
    }

    public int getAge() {
        return 20;
    }
}

public class Student implements Person {
    private String name;
    private int age;

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}