@Before
  public void setUp() throws Exception {

    calendarService = Mockito.mock(WorkDaysService.class);
    sickNoteDAO = Mockito.mock(SickNoteDAO.class);
    sickNotes = new ArrayList<>();

    Person person = TestDataCreator.createPerson();

    SickNote sickNote1 =
        TestDataCreator.createSickNote(
            person,
            new DateMidnight(2013, DateTimeConstants.OCTOBER, 7),
            new DateMidnight(2013, DateTimeConstants.OCTOBER, 11),
            DayLength.FULL);

    SickNote sickNote2 =
        TestDataCreator.createSickNote(
            person,
            new DateMidnight(2013, DateTimeConstants.DECEMBER, 18),
            new DateMidnight(2014, DateTimeConstants.JANUARY, 3),
            DayLength.FULL);

    sickNotes.add(sickNote1);
    sickNotes.add(sickNote2);

    Mockito.when(sickNoteDAO.findNumberOfPersonsWithMinimumOneSickNote(2013)).thenReturn(7L);
    Mockito.when(sickNoteDAO.findAllActiveByYear(2013)).thenReturn(sickNotes);

    Mockito.when(
            calendarService.getWorkDays(
                DayLength.FULL,
                new DateMidnight(2013, DateTimeConstants.OCTOBER, 7),
                new DateMidnight(2013, DateTimeConstants.OCTOBER, 11),
                person))
        .thenReturn(new BigDecimal("5"));

    Mockito.when(
            calendarService.getWorkDays(
                DayLength.FULL,
                new DateMidnight(2013, DateTimeConstants.DECEMBER, 18),
                new DateMidnight(2013, DateTimeConstants.DECEMBER, 31),
                person))
        .thenReturn(new BigDecimal("9"));

    statistics = new SickNoteStatistics(2013, sickNoteDAO, calendarService);
  }
  @Test(expected = IllegalArgumentException.class)
  public void testGetTotalNumberOfSickDaysInvalidDateRange() throws Exception {

    Mockito.when(sickNoteDAO.findAllActiveByYear(2015)).thenReturn(sickNotes);

    statistics = new SickNoteStatistics(2015, sickNoteDAO, calendarService);

    statistics.getTotalNumberOfSickDays();
  }
  @Test
  public void testGetAverageDurationOfDiseasePerPersonDivisionByZero() throws Exception {

    Mockito.when(sickNoteDAO.findNumberOfPersonsWithMinimumOneSickNote(2013)).thenReturn(0L);

    statistics = new SickNoteStatistics(2013, sickNoteDAO, calendarService);

    Assert.assertEquals(BigDecimal.ZERO, statistics.getAverageDurationOfDiseasePerPerson());
  }