public virtual IEnumerable PreviousPeriod(PXAdapter adapter)
        {
            ScheduleTransFilter filter     = Filter.Current as ScheduleTransFilter;
            FinPeriod           nextperiod = FiscalPeriodUtils.FindPrevPeriod(this, filter.FinPeriodID, true);

            if (nextperiod != null)
            {
                filter.FinPeriodID = nextperiod.FinPeriodID;
            }
            return(adapter.Get());
        }