def values(self) -> DataArray | None:
        """
        Return a normalized number array for the unique levels.

        Examples
        --------
        >>> a = xr.DataArray(["b", "a", "a", "b", "c"])
        >>> _Normalize(a).values
        <xarray.DataArray (dim_0: 5)> Size: 40B
        array([3, 1, 1, 3, 5])
        Dimensions without coordinates: dim_0

        >>> _Normalize(a, width=(18, 36, 72)).values
        <xarray.DataArray (dim_0: 5)> Size: 40B
        array([45., 18., 18., 45., 72.])
        Dimensions without coordinates: dim_0

        >>> a = xr.DataArray([0.5, 0, 0, 0.5, 2, 3])
        >>> _Normalize(a).values
        <xarray.DataArray (dim_0: 6)> Size: 48B
        array([0.5, 0. , 0. , 0.5, 2. , 3. ])
        Dimensions without coordinates: dim_0

        >>> _Normalize(a, width=(18, 36, 72)).values
        <xarray.DataArray (dim_0: 6)> Size: 48B
        array([27., 18., 18., 27., 54., 72.])
        Dimensions without coordinates: dim_0

        >>> _Normalize(a * 0, width=(18, 36, 72)).values
        <xarray.DataArray (dim_0: 6)> Size: 48B
        array([36., 36., 36., 36., 36., 36.])
        Dimensions without coordinates: dim_0

        """
        if self.data is None:
            return None

        val: DataArray
        if self.data_is_numeric:
            val = self.data
        else:
            arr = self._indexes_centered(self._data_unique_inverse)
            val = self.data.copy(data=arr.reshape(self.data.shape))

        return self._calc_widths(val)

        Return a normalized number array for the unique levels.

        Examples
        --------
        >>> a = xr.DataArray(["b", "a", "a", "b", "c"])
        >>> _Normalize(a).values
        <xarray.DataArray (dim_0: 5)> Size: 40B
        array([3, 1, 1, 3, 5])
        Dimensions without coordinates: dim_0

        >>> _Normalize(a, width=(18, 36, 72)).values
        <xarray.DataArray (dim_0: 5)> Size: 40B
        array([45., 18., 18., 45., 72.])
        Dimensions without coordinates: dim_0

        >>> a = xr.DataArray([0.5, 0, 0, 0.5, 2, 3])
        >>> _Normalize(a).values
        <xarray.DataArray (dim_0: 6)> Size: 48B
        array([0.5, 0. , 0. , 0.5, 2. , 3. ])
        Dimensions without coordinates: dim_0

        >>> _Normalize(a, width=(18, 36, 72)).values
        <xarray.DataArray (dim_0: 6)> Size: 48B
        array([27., 18., 18., 27., 54., 72.])
        Dimensions without coordinates: dim_0

        >>> _Normalize(a * 0, width=(18, 36, 72)).values
        <xarray.DataArray (dim_0: 6)> Size: 48B
        array([36., 36., 36., 36., 36., 36.])
        Dimensions without coordinates: dim_0

        
xarray/plot/utils.py