@Test
public void testPrev() throws Exception {

    LocalDate start = LocalDate.parse("2014-07-21");
    LocalDate end = LocalDate.parse("2014-07-27");
    assertTrue(mWeek.prev());
    assertEquals(start, mWeek.getFrom());
    assertEquals(end, mWeek.getTo());
    assertEquals(start, mWeek.getDays().get(0).getDate());
    assertEquals(end, mWeek.getDays().get(6).getDate());
}