public final void testHashCode() { Company company1 = new CompanyImpl(); Company company2 = new CompanyImpl(); assertTrue(company1.hashCode() == company2.hashCode()); company1.setPersistanceId(1); assertFalse(company1.hashCode() == company2.hashCode()); company1.setPersistanceId(0); company1.setName("world company"); assertFalse(company1.hashCode() == company2.hashCode()); }