public void Test4()
        {
            var bussinessHours = new BusinessHours
            {
                Days = new[]
                {
                    DayOfWeek.Monday,
                    DayOfWeek.Wednesday,
                    DayOfWeek.Thursday,
                    DayOfWeek.Saturday,
                    DayOfWeek.Sunday
                }
            };

            Assert.Collection(bussinessHours.DayPeriods,

                              period0 => Assert.Equal(DayPeriodFactory
                                                      .Make(DayOfWeek.Monday),
                                                      period0),

                              period1 => Assert.Equal(DayPeriodFactory
                                                      .Make(DayOfWeek.Wednesday, DayOfWeek.Thursday),
                                                      period1),

                              period2 => Assert.Equal(DayPeriodFactory
                                                      .Make(DayOfWeek.Saturday, DayOfWeek.Sunday),
                                                      period2)
                              );
        }
        void FormattedTest()
        {
            var periods = new[]
            {
                DayPeriodFactory
                .Make(DayOfWeek.Monday),
                DayPeriodFactory
                .Make(DayOfWeek.Wednesday, DayOfWeek.Thursday),
                DayPeriodFactory
                .Make(DayOfWeek.Saturday, DayOfWeek.Sunday),
            };

            Assert.Equal("Monday,Wednesday-Thursday,Saturday-Sunday", periods.Format());
        }
        public void Test6()
        {
            var bussinessHours = new BusinessHours
            {
                Days = new[]
                {
                    DayOfWeek.Monday,
                }
            };

            Assert.Collection(bussinessHours.DayPeriods,

                              period0 => Assert.Equal(DayPeriodFactory
                                                      .Make(DayOfWeek.Monday),
                                                      period0)
                              );
        }