code: def cancel_order(self, order_id, version=1):
          
          data = {'id': order_id}
          return self._post("cancel_order/", data=data, return_json=True,
                            version=version)
docs: Cancel the order specified by order_id.
  
          Version 1 (default for backwards compatibility reasons):
          Returns True if order was successfully canceled, otherwise
          raise a BitstampError.
  
          Version 2:
          Returns dictionary of the canceled order, containing the keys:
          id, type, price, amount