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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 slice_indexer(self, start=None, end=None, step=None, kind=None):
 """ For an ordered or unique index, compute the slice indexer for input labels and step. Parameters start : label, default None If None, defaults to the beginning end : label, default None If None, defaults to the end step : int, default None kind : string, default None Returns ------- indexer : slice Raises ------ KeyError : If key does not exist, or key is not unique and index is not ordered. Notes ----- This function assumes that the data is sorted, so use at your own peril Examples --------- This is a method on all index types. For example you can do: slice(1, 3) slice(1, 3) """

        start_slice, end_slice = self.slice_locs(start, end, step=step,
                                                 kind=kind)

        # return a slice
        if not is_scalar(start_slice):
            raise AssertionError("Start slice bound is non-scalar")
        if not is_scalar(end_slice):
            raise AssertionError("End slice bound is non-scalar")

        return slice(start_slice, end_slice, step)