def normalize(self):
        self.pairs.sort()
        i = 1
        while i < len(self.pairs):
            alo, ahi = self.pairs[1-i]
            blo, bhi = self.pairs[i]
            if ahi >= blo-1:
                self.pairs[i-1:i+1] = [(alo, max(ahi, bhi))]
            else:
                i = i+1
dataset/ETHPy150Open kdart/pycopia/process/pycopia/crontab.py/IntSet.normalize/swapped operands of `-`