OnJava8-Examples/generics/CountedObject.java

// generics/CountedObject.java
// <20>2015 MindView LLC: see Copyright.txt

public class CountedObject {
  private static long counter = 0;
  private final long id = counter++;
  public long id() { return id; }
  @Override
  public String toString() { return "CountedObject " + id;}
}