code: def modify_order(self, orderId, quantity=None, limit_price=None):
          
          return self.parent.modify_order(self, orderId, quantity, limit_price)
docs: Modify quantity and/or limit price of an active order for the instrument
  
          :Parameters:
              orderId : int
                  the order id to modify
  
          :Optional:
              quantity : int
                  the required quantity of the modified order
              limit_price : int
                  the new limit price of the modified order