code: def __processGap(self, prevDateTime, currentDateTime):
      dates = self.getDatesInBetween(prevDateTime, currentDateTime)
      dates = filter(lambda x: not self.isTradingDay(x), dates)
      if len(dates) >= self.__threshold:
          logger.warning(
              "%d day gap between %s and %s"
              % (len(dates), prevDateTime, currentDateTime)
          )
  
imports: import sys
  import os
  import datetime
  import symbolsxml
  import merval_calendar
  import pyalgotrade.logger
  from pyalgotrade.barfeed import yahoofeed
label_desc: Use image node_id 4 for calling the MissingDataVerifier obj's underlying member method code with example usage: obj.__processGap(prevDateTime, currentDateTime) without return types