code: def clean(self):
          ''' priorDays is required for Generic Repeated Expenses to avoid infinite loops '''
          if not self.priorDays and not self.startDate:
              raise ValidationError(_(
                  'Either a start date or an "up to __ days in the past" limit is required ' +
                  'for repeated expense rules that are not associated with a venue or a staff member.'
              ))
          super(GenericRepeatedExpense,self).clean(f clean(self):
          ''' priorDays is required for Generic Repeated Expenses to avoid infinite loops '''
          if not self.priorDays and not self.startDate:
              raise ValidationError(_(
                  'Either a start date or an "up to __ days in the past" limit is required ' +
                  'for repeated expense rules that are not associated with a venue or a staff member.'
              ))
          super(GenericRepeatedExpense,self).clean()
docs: priorDays is required for Generic Repeated Expenses to avoid infinite loops