ValueObject

globalState4.java

class Book {

  private String title;
  private String author;
  private int price;

  public Book(String title, String author, int price) {
    this.title = title;
    this.author = author;
    this.price = price;
  }

  public String title() {
    return title;
  }
 
  public String author() {
    return author;
  }

  public int price() {
    return price
  }

}