pm.currentTransaction().begin();
p = (Product) query.execute(id + "bis"); //no query
assertNotNull("Null value for " + id + "bis", p);
pm.currentTransaction().commit();
pm.evictAll();
pm.currentTransaction().begin();
p = (Product) query.execute(id + "bis"); //query
assertNotNull("Null value for " + id + "bis", p);
pm.currentTransaction().commit();