code: def enterShortPosition(self, bars):
      raise Exception("Not implemented")
  
imports: from .None import common
  from pyalgotrade import strategy
  from pyalgotrade.barfeed import yahoofeed
  from pyalgotrade.technical import ma
  from pyalgotrade.technical import cross
label_desc: Use image node_id 3 for calling the SMACrossOverStrategy obj's underlying member method code with example usage: obj.enterShortPosition(bars) without return types