code: def __init__(self):
      self.lines.a = b = self.data.close - self.data.high
      self.lines.b = btind.SMA(b, period=20)
  
file_path: backtrader/samples/memory-savings/memory-savings.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import argparse
  import sys
  import backtrader
  import backtrader.feeds
  import backtrader.indicators
  import backtrader.utils.flushfile
label_desc: Use image node_id 1 to create a new TestInd object from inherited base classes: bt with example: obj = TestInd()