class_docstr: A :class:`pyalgotrade.stratanalyzer.StrategyAnalyzer` that calculates
  max. drawdown and longest drawdown duration for the portfolio.
code: def __init__(self):
      super(DrawDown, self).__init__()
      self.__maxDD = 0
      self.__longestDDDuration = datetime.timedelta()
      self.__currDrawDown = DrawDownHelper()
  
file_path: pyalgotrade/pyalgotrade/stratanalyzer/drawdown.py
imports: from pyalgotrade import stratanalyzer
  import datetime
label_desc: Use image node_id 1 to create a new DrawDown object from inherited base classes: stratanalyzer with example: obj = DrawDown()