@Test
public void testApply_period() {
openRabbitPreferences();
int numDays = 30;
SWTBotSpinner datePeriod = bot.spinner();
datePeriod.setSelection(numDays);
bot.button("Apply").click();
assertEquals(numDays, RabbitUI.getDefault().getDefaultDisplayDatePeriod());
numDays = 7;
datePeriod.setSelection(numDays);
bot.button("Apply").click();
assertEquals(numDays, RabbitUI.getDefault().getDefaultDisplayDatePeriod());
bot.activeShell().close();
}