def test_data_values_should_use_same_style_for_dd_mm_yyyy_format(self):
        ws = Mock(spec=Worksheet)
        date_1 = ExcelDate(datetime.datetime(2012, 04, 12), 'dd.mm.yyyy')
        date_2 = ExcelDate(datetime.datetime(2012, 05, 29), 'dd.mm.yyyy')
        row = [date_1, date_2]