code: def peekDateTime(self):
      ret = None
      if self.__nextPos < len(self.__bars):
          ret = self.__bars[self.__nextPos].getDateTime()
      return ret
  
imports: import abc
  from pyalgotrade import bar
  from pyalgotrade.dataseries import bards
  from pyalgotrade import feed
  from pyalgotrade import dispatchprio
label_desc: Use image node_id 7 for calling the OptimizerBarFeed obj's underlying member method code with example usage: obj.peekDateTime() and returns: ret