gistfile1.txt

   Mapped classes are abstract where abstract annotated
   getters that take a Query/Fetch lisener. Object will be proxied, if
   an abstract getter is invoked, fetch and call listener. 

   abstract class Score implements Entity {

       @Column(primaryKey=true)
       Private int id;
       private date;  
       private int score;
      
       @Column(foreignKey=User.class)
       private int userId;

       @Relation(User.class)
       public abstract void getUser(FetchListener<User> listener);              
      
       ...
   }
   
   abstract class User implements Entity {
   
       @Column(primaryKey=true)
       private int id;
       private String name;

       @Relation(Score.class)
       public abstract void getScores(QueryListener<Score> listener);

       ...
   }