@Test
public void given4EmployeesOneWithTax_whenGetUnprocessedEmployeeIds_thenReturnCorrectList() {

    Employee employee1 = anEmployee();
    Employee employee2 = anEmployee();
    Employee employee3 = anEmployee();
    Employee employee4 = anEmployee();
    asList(employee1, employee2, employee3, employee4).forEach(employeeRepository::save);
    TaxCalculation tax = new TaxCalculationTestBuilder()
            .withEmployee(employee2)
            .withYear(2014)
            .withMonth(5)
            .build();
    taxCalculationRepository.save(tax);
    assertThat(taxCalculationRepository.getUnprocessedEmployeeIds(2014L, 5L, 0L)).containsOnly(
            employee1.getId(),
            employee3.getId(),
            employee4.getId()
    );
}