question: public static int deleteExpiredHistory ( EntityManager em ) { requireArgument ( em != null , "Entity manager cannot be null." ) ; Query query = em . createNamedQuery ( "History.cullExpired" ) ; query . setParameter ( "expirationDate" , new Date ( System . currentTimeMillis ( ) - ( 2 * MILLIS_PER_WEEK ) ) ) ; return query . executeUpdate ( ) ; }
target:  Deletes the old job history.