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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 save_all_figures_todir(self, dirname):
 """Save all figure in dirname."""

        fignames = []
        for thumbnail in self._thumbnails:
            fig = thumbnail.canvas.fig
            fmt = thumbnail.canvas.fmt
            fext = {'image/png': '.png',
                    'image/jpeg': '.jpg',
                    'image/svg+xml': '.svg'}[fmt]

            figname = get_unique_figname(dirname, 'Figure', fext)
            save_figure_tofile(fig, fmt, figname)
            fignames.append(figname)
        return fignames