code: def _start(self):
      # Override to add specific attributes
      self.timeframe = self.p.timeframe or self.data._timeframe
      self.compression = self.p.compression or self.data._compression
  
      self.dtcmp, self.dtkey = self._get_dt_cmpkey(
          datetime.datetime.min
      )
      super(TimeFrameAnalyzerBase, self)._start()
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import calendar
  from collections import OrderedDict
  import datetime
  import pprint
  import backtrader
  from backtrader import TimeFrame
  from backtrader.utils.py3 import MAXINT, with_metaclass
label_desc: Use image node_id 1 for calling the TimeFrameAnalyzerBase obj's underlying member method code with example usage: obj._start() without return types