@Entity(name = "Task")
 public static class Task {

   @Id
   private Long id;
   @OneToMany(mappedBy = "task")
   @OrderBy("assignee ASC")
   private List<TaskVersion> taskVersions;
 }

 @Entity(name = "TaskVersion")
 public static class TaskVersion {
   @Id
   private Long id;

   @ManyToOne(fetch = FetchType.EAGER)
   @JoinColumn(name = "assignee", nullable = true)
   private User assignee;

   @ManyToOne(fetch = FetchType.EAGER)
   @JoinColumn(name = "task_id", nullable = false)
   private Task task;
   private String name;
 }

 @Entity(name = "UUser")
 public static class User {
   @Id
   private Long id;   
   private String name;
 }