code: def setAlive(self):
      self.__lastSeen = time.time()
      self.__kaSent = None
  
imports: import json
  import time
  import threading
  import six
  from ws4py.client import tornadoclient
  import tornado
  import pyalgotrade.logger
label_desc: Use image node_id 4 for calling the KeepAliveMgr obj's underlying member method code with example usage: obj.setAlive() without return types