code: def __init__(self, feed, instrument, bBandsPeriod):
      super(BBands, self).__init__(feed)
      self.__instrument = instrument
      self.__bbands = bollinger.BollingerBands(
          feed[instrument].getCloseDataSeries(), bBandsPeriod, 2
      )
  
file_path: pyalgotrade/samples/bbands.py
imports: from __future__ import print_function
  from pyalgotrade import strategy
  from pyalgotrade import plotter
  from pyalgotrade.tools import quandl
  from pyalgotrade.technical import bollinger
  from pyalgotrade.stratanalyzer import sharpe
  from pyalgotrade import broker
label_desc: Use image node_id 1 to create a new BBands object from inherited base classes: strategy with example: obj = BBands(feed, instrument, bBandsPeriod)