anchor.diff:      public void setPages(double pages) {
           this.pages = pages;
       }
  -
   }
   ----
   
  
positive.code: 
  public class Book {
  
  
      @NotBlank(message="Title cannot be blank")
      private String title;
  
      @NotBlank(message="Author cannot be blank")
      private String author;
  
      @Min(message="Author has been very lazy", value=1)
  
negative.code:         res.message = "woohoo!";
      } else {
          res.success = false;
          res.message = violations.stream()
              .map(cv -> cv.getMessage())
              .collect(Collectors.joining(", "));
      }
      return res;
  }
  