@Entity
@Table(name="mytable")
public class Element{
    @JoinTable( name="map_table" )
    @CollectionOfElements(fetch=FetchType.EAGER)
    @Cascade(value = CascadeType.DELETE_ORPHAN)
    @Enumerated(value=EnumType.ORDINAL)
    @MapKey( columns = { @Column( name="myenum" ) } )
    @Column( name="myvalue")
    Map<MyEnum,Integer> someMap;

    @OneToOne
    Element prev;
   
    [...]
}