def _rename(
        self,
        name_dict: Mapping[Any, Hashable] | None = None,
        **names: Hashable,
    ) -> Self:
        """Also used internally by DataArray so that the warning (if any)
        is raised at the right stack level.
        """
        name_dict = either_dict_or_kwargs(name_dict, names, "rename")
        for k in name_dict.keys():
            if k not in self and k not in self.dims:
                raise ValueError(
                    f"cannot rename {k!r} because it is not a "
                    "variable or dimension in this dataset"
                )

            create_dim_coord = False
            new_k = name_dict[k]

            if k == new_k:
                continue  # Same name, nothing to do

            if k in self.dims and new_k in self._coord_names:
                coord_dims = self._variables[name_dict[k]].dims
                if coord_dims == (k,):
                    create_dim_coord = True
            elif k in self._coord_names and new_k in self.dims:
                coord_dims = self._variables[k].dims
                if coord_dims == (new_k,):
                    create_dim_coord = True

            if create_dim_coord:
                warnings.warn(
                    f"rename {k!r} to {name_dict[k]!r} does not create an index "
                    "anymore. Try using swap_dims instead or use set_index "
                    "after rename to create an indexed coordinate.",
                    UserWarning,
                    stacklevel=3,
                )

        variables, coord_names, dims, indexes = self._rename_all(
            name_dict=name_dict, dims_dict=name_dict
        )
        return self._replace(variables, coord_names, dims=dims, indexes=indexes)
Also used internally by DataArray so that the warning (if any)
        is raised at the right stack level.
        
xarray/core/dataset.py