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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def argsort(self, *args, **kwargs):
 """ Returns the indices that would sort the index and its underlying data. Returns ------- argsorted : numpy array See Also -------- numpy.ndarray.argsort """

        nv.validate_argsort(args, kwargs)

        if self._step > 0:
            return np.arange(len(self))
        else:
            return np.arange(len(self) - 1, -1, -1)