Method setTitle

reflection/Position.java:20–24

(String newTitle)

  }
  public String getTitle() { return title; }
  public void setTitle(String newTitle) {
    // Throws EmptyTitleException if newTitle is null:
    title = Optional.ofNullable(newTitle)
      .orElseThrow(EmptyTitleException::new);
  }
  public Person getPerson() { return person; }
  public void setPerson(Person newPerson) {
    // Uses empty Person if newPerson is null: