docs: def cancel_order(self, order_id):
          """
          Send a request to cancel an order, return the response.
  
          Arguments:
          order_id - the order id to cancel
          """
          request = '/v1/order/cancel'
          url = self.base_url + request
          params = {
              'request': request,
              'nonce': self.get_nonce(),
              'order_id': order_id
          }
  
          return requests.post(url, headers=self.prepare(params))