public void CurrentFirstDayOfWeekInMonthShouldReturnExpectedResult()
        {
            using ( ShimsContext.Create() )
            {
                ShimDateTime.TodayGet = () => new DateTime( 2013, 6, 1 );

                var expected = new DateTime( 2013, 6, 3 );
                var target = new GregorianCalendar();
                var actual = target.CurrentFirstDayOfWeekInMonth( DayOfWeek.Monday );

                Assert.Equal( expected.Date, actual.Date );
            }
        }