def __add__(self, other):
        "return merged interval spanning both self and other intervals"
        if self.path is not other.path:
            raise ValueError('incompatible intervals cannot be merged.')
        if other.start < self.start:
            start = self.start
        else:
            start = other.start
        if self.stop > other.stop:
            stop = self.stop
        else:
            stop = other.stop
        if stop == 0:
            # Have to handle the boundary case specially because of Python
            # conventions.
            stop = None
        return self.classySlice(self.path, start, stop, self.step)
dataset/ETHPy150Open cjlee112/pygr/pygr/sequence.py/SeqPath.__add__/swapped operands of `<`