anchor.diff:  ----
   @Entity
   public class Comedian {
  -  
  +
     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
     private ObjectId id;
  
positive.code: ----
  @Entity
  public class DistributedRevisionControl {
    
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
  
negative.code: 
  [source, JSON]
  ----
  {
      "_id" : "GuitarPlayer",
      "next_val" : 101
  }
  