def __addPastReturns(self, instrument, event):
        begin = (event.getLookBack() + 1) * -1
        for t in xrange(begin, 0):
            try:
                ret = self.__rets[instrument][t]
                if ret is not None:
                    event.setValue(t+1, ret)
            except __HOLE__:
                pass
dataset/ETHPy150Open gbeced/pyalgotrade/pyalgotrade/eventprofiler.py/Profiler.__addPastReturns