code: def quantity_update(self, num_iid, quantity, session, sku_id=None, outer_id=None, aType=None):
          '''taobao.item.quantity.update 宝贝/SKU库存修改
          
          提供按照全量或增量形式修改宝贝/SKU库存的功能'''
          request = TOPRequest('taobao.item.quantity.update')
          request['num_iid'] = num_iid
          request['quantity'] = quantity
          if sku_id!=None:
              request['sku_id'] = sku_id
          if outer_id!=None:
              request['outer_id'] = outer_id
          if aType!=None:
              request['type'] = aType
          self.create(self.execute(request, session)['item'])
          return self quantity_update(self, num_iid, quantity, session, sku_id=None, outer_id=None, aType=None):
          '''taobao.item.quantity.update 宝贝/SKU库存修改
          
          提供按照全量或增量形式修改宝贝/SKU库存的功能'''
          request = TOPRequest('taobao.item.quantity.update')
          request['num_iid'] = num_iid
          request['quantity'] = quantity
          if sku_id!=None:
              request['sku_id'] = sku_id
          if outer_id!=None:
              request['outer_id'] = outer_id
          if aType!=None:
              request['type'] = aType
          self.create(self.execute(request, session)['item'])
          return self
docs: taobao.item.quantity.update 宝贝/SKU库存修改
          
          提供按照全量或增量形式修改宝贝/SKU库存的功能