@Test
public void detailsForMonthWithCategories() {

	transactions = createTransactionsWithCategories();
	doReturn(transactions).when(transactionsService).retrieve();
	PeriodDetails detailsForMonth = service.detailsForMonth(201501);
	assertEquals("January 2015", detailsForMonth.getName());
	assertEquals(2, detailsForMonth.getCategories().size());
	CategorySummary categorySummary = detailsForMonth.getCategories().get(0);
	assertEquals("Fries", categorySummary.getName());
	assertEquals(-1500L, categorySummary.getAmount());
	categorySummary = detailsForMonth.getCategories().get(1);
	assertEquals("Burgers", categorySummary.getName());
	assertEquals(102300L, categorySummary.getAmount());
}