Java - hierarchy relationship in an enum

Person.java

// From https://stackoverflow.com/questions/44654291/is-it-good-practice-to-use-ordinal-of-enum

public enum Person {
  GRANDPARENT(null),
  PARENT(GRANDPARENT),
  CHILD(PARENT);

  private final Person parent;

  private Person(Person parent) {
    this.parent = parent;
  }

  public final Parent getParent() {
    return parent;
  }
}