de> respectively.  The latter
 are to be preferred for new applications.

 <p> The semantics of requesting locks of type
 <code>LockModeType.OPTIMISTIC</code> and
 <code>LockModeType.OPTIMISTIC_FORCE_INCREMENT</code> are the
 following.

 <p> If transaction T1 calls for a lock of type 
 <code>LockModeType.OPTIMISTIC</code> on a versioned object, 
 the entity manager must ensure that neither of the following 
 phenomena can occur:
 <ul>
   <li> P1 (Dirty read): Transaction T1 modifies a row. 
 Another transa