code: def start(self):
      header = [
          "Datetime",
          "Open",
          "High",
          "Low",
          "Close",
          "Volume",
          "OpenInterest",
          "SMA",
      ]
      print(", ".join(header))
  
      self.done = False
  
file_path: backtrader/samples/vctest/vctest.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import argparse
  import datetime
  import backtrader
  from backtrader.utils import flushfile
  from backtrader.utils.py3 import string_types
label_desc: Use image node_id 8 for calling the TestStrategy obj's underlying member method code with example usage: obj.start() without return types