code: def onBars(self, bars):
      raise Exception("oh no!")
  
file_path: pyalgotrade/testcases/optimizer_test.py
imports: import sys
  import logging
  from .None import common
  from pyalgotrade.optimizer import local
  from pyalgotrade import strategy
  from pyalgotrade.barfeed import yahoofeed
  import sma_crossover
label_desc: Use image node_id 2 for calling the FailingStrategy obj's underlying member method code with example usage: obj.onBars(bars) without return types