How to use the wpgtk.data.sample.create_sample function in wpgtk

def render_theme(self):
        sample_path = files.get_sample_path(self.selected_file)

        try:
            self.color_list = color.get_color_list(self.selected_file)
        except SystemExit:
            self.color_list = themer.set_fallback_theme(self.selected_file)
        self.render_buttons()

        try:
            self.pixbuf_sample = GdkPixbuf.Pixbuf\
                .new_from_file_at_size(sample_path, width=500, height=300)
        except:
            sample.create_sample(self.color_list, sample_path)
            self.pixbuf_sample = GdkPixbuf.Pixbuf\
                .new_from_file_at_size(sample_path, width=500, height=300)

        self.sample.set_from_pixbuf(self.pixbuf_sample)
        self.parent.sample.set_from_pixbuf(self.pixbuf_sample)

def render_sample(self):
        sample.create_sample(self.color_list)
        sample_path = os.path.join(WALL_DIR, ".tmp.sample.png")
        self.pixbuf_sample = GdkPixbuf.Pixbuf.new_from_file_at_size(
                str(sample_path),
                width=500,
                height=300)
        self.sample.set_from_pixbuf(self.pixbuf_sample)