Category cat1 = new Category(null,CategoryEnum.COMVALORTIPO1);

Item it1 = new Item(null, "Item 1", "local 1", "who find 1", cat1);

Item it2 = new Item(null, "Item 2", "local 2", "who find 2", cat1);

Lost lo1 = new Lost(null, sdf.parse("20/07/2019 11:05"), it1);

it1.setLost(lo1);

Lost lo2 = new Lost(null, sdf.parse("21/07/2019 12:05"), it2);

it2.setLost(lo2);

Claim claim1 = new Claim(null, sdf.parse("22/08/2019 23:59"), it1);

it1.setClaim(claim1);