code: def get_referenced_object(self):
          
  
          if self._BillingInvoice is not None:
              return self._BillingInvoice
  
          if self._DraftPayment is not None:
              return self._DraftPayment
  
          if self._MasterCardAction is not None:
              return self._MasterCardAction
  
          if self._Payment is not None:
              return self._Payment
  
          if self._PaymentBatch is not None:
              return self._PaymentBatch
  
          if self._RequestResponse is not None:
              return self._RequestResponse
  
          if self._ScheduleInstance is not None:
              return self._ScheduleInstance
  
          if self._TabResultResponse is not None:
              return self._TabResultResponse
  
          if self._WhitelistResult is not None:
              return self._WhitelistResult
  
          raise exception.BunqException(self._ERROR_NULL_FIELDS)
docs: :rtype: core.BunqModel
          :raise: BunqException