agent.find(missing)  -> null
agent.get(missing)   -> EntityNotFoundException

EntityAgent, same id twice in one transaction:
  same instance? false
  SQL (2 statements)
  select b1_0.isbn,b1_0.price,b1_0.publisher_id,b1_0.title,b1_0.version,b1_0.views from book b1_0 where b1_0.isbn=?
  select b1_0.isbn,b1_0.price,b1_0.publisher_id,b1_0.title,b1_0.version,b1_0.views from book b1_0 where b1_0.isbn=?

EntityManager, same id twice in one transaction:
  same instance? true
  SQL (1 statement)
  select b1_0.isbn,b1_0.price,b1_0.publisher_id,b1_0.title,b1_0.version,b1_0.views from book b1_0 where b1_0.isbn=?

agent.getMultiple(3 ids) returned 3 books
  SQL (1 statement)
  select b1_0.isbn,b1_0.price,b1_0.publisher_id,b1_0.title,b1_0.version,b1_0.views from book b1_0 where b1_0.isbn in (?,?,?)