Description of problem:

@MapKey is not designed for using Embeddables in maps, so @MapKeyColumn should be used. However when using the following annotation you get a "Repeated Column in Mapping" error:

	@ElementCollection
	@CollectionTable(name = "TRANSACTIONS_EVENTS",
			joinColumns = @JoinColumn(name = "TRANSACTION_ID") )
	@MapKeyColumn(name = "type", insertable=false, updateable=false)
	@MapKeyEnumerated(EnumType.STRING)
	private Map<EventType, TransactionEvent> events = new HashMap<EventType, TransactionEvent>();