1. I am getting the following error when I run multi-core optimization.
   AttributeError: Can't pickle local object 'GenericCSVData.start.<locals>.<lambda>'

2. Also, how can I close all my open positions or get the total (realized+unrealized) profit after each optimization run? Currently, I am getting only the realized PnL using the following line in the stop function.
   round(self.broker.get_value(), 2)

I am executing a buy (market) order on the next candles opening price after my strategy gives signal to buy. My stop loss is a function of the price at which the order is executed. How should I implement this stoploss in backtrader