Java：如何构造给定基类实例的派生类实例？

Given:

@lombok.Data // generates get/set methods for all data members
public class Base {
    private int x;
    private double y;
    private String z;
    ...
}


public class Derived extends Base {
    private int extra;
    public String addedMethod() { ... }
}
@lombok.Data // generates get/set meth