code: def close_changer(data, *args, **kwargs):
      data.close[0] += 50.0 * random.randint(-1, 1)
      return False
  
file_path: backtrader/samples/future-spot/future-spot.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import argparse
  import random
  import backtrader
label_desc: Use image node_id 1 for calling a global function with example usage: close_changer(data) and returns: False