code: def __openNewPosition(self, quantity, price):
      self.__avgPrice = price
      self.__position = quantity
      self.__totalCommited = self.__avgPrice * abs(self.__position)
  
imports: import math
  from pyalgotrade import stratanalyzer
  from pyalgotrade import observer
  from pyalgotrade import dataseries
label_desc: Use image node_id 8 for calling the PositionTracker obj's underlying member method code with example usage: obj.__openNewPosition(quantity, price) without return types