private WorkSchedule FetchWorkSchedule(short year, short month)
 {
     return(Kernel.TryGetValue(Standards.FormatYearMonth(year, month), out WorkSchedule workSchedule)
         ? workSchedule
         : WorkSchedule.New(Database,
                            NameValue.Set <WorkSchedule>(p => p.Manager, Manager).
                            Set(p => p.Year, year).
                            Set(p => p.Month, month).
                            Set(p => p.Workers, new long[0])));
 }