cur_lo1, cur_hi1, pre_lo, pre_hi, cur_lo2, cur_hi2 = bounds
pre_lo_improves = self.improves(pre_lo, cur_lo1, cur_hi1)
pre_hi_improves = self.improves(pre_hi, cur_lo1, cur_hi1)
cur_lo1, cur_hi1, pre_lo, pre_hi, cur_lo2, cur_hi2 = bounds
pre_lo_improves = self.improves(pre_lo, cur_lo1, cur_hi1)
pre_hi_improves = self.improves(pre_hi, cur_lo1, cur_hi1)