lyc_code/src/test/java/maslaos/shejimos/Person.java

package maslaos.shejimos;

public class Person {
    int a;
    int b;
    int c;
    int d;

    private Person(){
        A a = new A(){};

    }
    static class PersonBuilder{
        Person p =new Person();

        PersonBuilder basic(int a,int b){
            p.a=a;
            p.b=b;
            return this;
        }

        PersonBuilder c(int c){
            p.c=c;
            return this;
        }

        PersonBuilder d(int d){
            p.d=d;
            return this;
        }

        Person builder(){
            return p;
        }

    }

    abstract  class  A{
//        abstract void m();

    }

    public static void main(String[] args) {
        Person person = new PersonBuilder()
                .basic(1, 2)
                .c(3)
                .d(4)
                .builder();


    }

}