auto', use the current figure
            edgecolor.

        backend : str, optional
            Use a non-default backend to render the file, e.g. to render a
            png file with the "cairo" backend rather than the default "agg",
            or a pdf file with the "pgf" backend rather than the default
            "pdf".  Note that the default backend is normally sufficient.  See
            :ref:`the-builtin-backends` for a list of valid backends for each
            file format.  Custom backends can be referenced as "module://...".

        orientation : {'landscape', 'portrait'}
            Currently only supported by the postscript backend.

        papertype : str
            One of 'letter', 'legal', 'executive', 'ledger', 'a0' through
            'a10', 'b0' through 'b10'. Only supported for postscript
            output.

        transparent : bool
            If *True*, the Axes patches will all be transparent; the
            Figure patch will also be transparent unless *facecolor*
            and/or *edgecolor* are specified via kwargs.

            If *False* has no effect and the color of the Axes and
            Figure patches are unchanged (unless the Figure patch
            is specified via the *facecolor* and/or *edgecolor* keyword
            arguments in which case those colors are used).

            The transparency of these patches will be restored to their
            original values upon exit of this function.

            This is useful, for example, for displaying
            a plot on top of a colored background on a web page.

        bbox_extra_artists : list of `~matplotlib.artist.Artist`, optional
            A list of extra artists that will be considered when the
            tight bbox is calculated.

        pil_kwargs : dict, optional
            Additional keyword arguments that are passed to
            `PIL.Image.Image.save` when saving the figure.

        rC