public void PreviousQuarterTest() { TimeTool.PreviousQuarter(QuarterKind.First).Quarter.Should().Be(QuarterKind.Fourth); TimeTool.PreviousQuarter(QuarterKind.Second).Quarter.Should().Be(QuarterKind.First); TimeTool.PreviousQuarter(QuarterKind.Third).Quarter.Should().Be(QuarterKind.Second); TimeTool.PreviousQuarter(QuarterKind.Fourth).Quarter.Should().Be(QuarterKind.Third); }