code: def start(self):
      trades = self._getNewTrades()
      # Store the last trade id since we'll start processing new ones only.
      if len(trades):
          self.__lastTradeId = trades[-1].getId()
          common.logger.info(
              "Last trade found: %d" % (self.__lastTradeId)
          )
  
      super(TradeMonitor, self).start()
  
imports: import threading
  import time
  from six.moves import queue
  from pyalgotrade import broker
  from pyalgotrade.bitstamp import httpclient
  from pyalgotrade.bitstamp import common
label_desc: Use image node_id 4 for calling the TradeMonitor obj's underlying member method code with example usage: obj.start() without return types