public static bool HaveDatesOutOfRangeOf(this List <DateRange> dateRanges, DateRange other)
 {
     return(dateRanges.Any(dateRange => !other.DateInDateRange(dateRange.StartDate) || !other.DateInDateRange(dateRange.EndDate)));
 }
        public static List <DateTime> GetDatesMissingFrom(this List <DateRange> dateRanges, DateRange other)
        {
            var sequence = GetDaysFromDateRangeCollection(dateRanges);
            var gaps     = other.Days.Except(sequence).ToList();

            return(gaps);
        }
        public static bool HaveDatesMissingFrom(this List <DateRange> dateRanges, DateRange other)
        {
            var gaps = dateRanges.GetDatesMissingFrom(other);

            return(gaps.Count > 0);
        }