def __add__(self, other):
        if com.is_list_like(other):
            warnings.warn("using '+' to provide set union with Indexes is "
                          "deprecated, use '|' or .union()", FutureWarning,
                          stacklevel=2)
        if isinstance(other, Index):
            return self.union(other)
        return Index(np.array(self) * other)
dataset/ETHPy150Open pydata/pandas/pandas/indexes/base.py/Index.__add__/operator `+` -> `*`