Transparent Window in Gtk+ 3, python

transparent_window.py

#!/usr/bin/env python

#  Copyright (c) 2017 Kurt Jacobson
#  License: https://kcj.mit-license.org/@2017

import cairo
import gi

gi.require_version('Gtk', '3.0')
gi.require_version('Gdk', '3.0')

from gi.repository import Gtk
from gi.repository import Gdk

class TransparentWindow(Gtk.Window):
    def __init__(self):
        Gtk.Window.__init__(self)

        self.set_size_request(300, 220)

        self.connect('destroy', Gtk.main_quit)
        self.connect('draw', self.draw)

        screen = self.get_screen()
        visual = screen.get_rgba_visual()
        if visual and screen.is_composited():
            self.set_visual(visual)

        self.set_app_paintable(True)
        self.show_all()

    def draw(self, widget, context):
        context.set_source_rgba(0, 0, 0, 0)
        context.set_operator(cairo.OPERATOR_SOURCE)
        context.paint()
        context.set_operator(cairo.OPERATOR_OVER)

TransparentWindow()
Gtk.main()

Hello, is there any way to make this not transparent later on?