code: def _dt_window_size(self, start_dt, end_dt):
      return len(
          self.trading_calendar.minutes_in_range(start_dt, end_dt)
      )
  
imports: from abc import ABCMeta, abstractmethod
  from numpy import full, nan, int64, zeros
  from six import iteritems, with_metaclass
  from zipline.utils.memoize import lazyval
label_desc: Use image node_id 1 for calling the AssetDispatchMinuteBarReader obj's underlying member method code with example usage: obj._dt_window_size(start_dt, end_dt) and returns: len