em.persist(lawnmowers);
em.persist(screws);
em.flush();
Sale s1 = createSale(alice, 2005, 2, 2, 10);
Sale s2 = createSale(alice, 2004);
Sale s3 = createSale(carol, 2003);
Sale s4 = createSale(carol, 2004, 2, 2, 5);
Sale s5 = createSale(dave, 2001);
Sale s6 = createSale(eve, 2005);
em.persist(s1);
em.persist(s2);
em.persist(s3);
em.persist(s4);
em.persist(s5);