EntityManager.persist x 5000 in one transaction
  entities held in the persistence context at the end: 5000
  entity inserts: 5000   statements prepared: 1

EntityAgent.insert x 5000 in one transaction
  entities held anywhere: 0 (a StatelessSession has no persistence context)
  entity inserts: 5000   statements prepared: 5000

EntityAgent.insertMultiple(list of 5000)
  entity inserts: 5000   statements prepared: 1

publisher.id before insert: null
publisher.id after insert:  1 (insert() itself returns void)