, default: 'baseline'
            Alignment of boxes.

        mode : {'fixed', 'expand', 'equal'}, default: 'fixed'
            The packing mode.

            - 'fixed' packs the given `.Artist`\s tight with *sep* spacing.
            - 'expand' uses the maximal available space to distribute the
              artists with equal spacing in between.
            - 'equal': Each artist an equal fraction of the available space
              and is left-aligned (or top-aligned) therein.

        children : list of `.Artist`
            The artists to pack.

        Notes
        -----
        *pad* and *sep* are in points and will be scaled with the renderer
        dpi, while *width* and *height* are in pixels.
        N)	rn