code: def __init__(self):
      sma1 = bt.indicators.SMA(period=self.p.p1)
      sma2 = bt.indicators.SMA(period=self.p.p2)
      self.lines.signal = sma1 - sma2
  
file_path: backtrader/samples/signals-strategy/signals-strategy.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import argparse
  import collections
  import datetime
  import backtrader
label_desc: Use image node_id 1 to create a new SMAExitSignal object from inherited base classes: bt with example: obj = SMAExitSignal()