def toggle(self):
        """Toggle :obj:`ToggledFrame.interior` opened or closed."""
        if self._open:
            self._open = False
            self.__checkbutton_var.set(False)
            self.interior.grid_forget()
            self._checkbutton.config(image=self._closed_image)
        else:
            self._open = True
            self.__checkbutton_var.set(True)
            self.interior.grid(row=1, column=0, sticky="nswe")
            self._checkbutton.config(image=self._open_image)
Toggle :obj:`ToggledFrame.interior` opened or closed.