e></a> is called and the entity already exists. The
 current transaction, if one is active, will be marked for rollback.
 <p>
 If the entity already exists, the <code>EntityExistsException</code> may be thrown when
 the persist operation is invoked, or the <code>EntityExistsException</code> or another
 <code>PersistenceException</code> may be thrown at flush or commit time.
 <p> The current transaction, if one is active and the persistence context
 has been joined to it, will be marked for rollback.</div>
<