code: def cancelOrder(self, orderId):
      url = "https://www.bitstamp.net/api/cancel_order/"
      params = {"id": orderId}
      jsonResponse = self._post(url, params)
      if jsonResponse != True:
          raise Exception("Failed to cancel order")
  
imports: import time
  import datetime
  import hmac
  import hashlib
  import requests
  import threading
  from pyalgotrade.utils import dt
  from pyalgotrade.bitstamp import common
  import logging
label_desc: Use image node_id 6 for calling the HTTPClient obj's underlying member method code with example usage: obj.cancelOrder(orderId) without return types