title: How to change/switch windows using Gtk.Application Gtk+3 Glade Python?
body: <p>I read this tutorial-
  <a href="https://python-gtk-3-tutorial.readthedocs.io/en/latest/application.html" rel="nofollow noreferrer">https://python-gtk-3-tutorial.readthedocs.io/en/latest/application.html</a></p>
  
  <p>It says in the first para -</p>
  
  <blockquote>
    <p>Gtk.Application encompasses many repetitive tasks that a modern
    application needs such as handling multiple instances, D-Bus
    activation, opening files, command line parsing, <strong>startup/shutdown</strong>,
    <strong>menu management</strong>, <strong>window management</strong>, and more.</p>
  </blockquote>
  
  <p>How do I do startup/shutdown, window management and menu management using Gtk.Application? I could not find any tutorials, examples or API documentation. Can anyone suggest how to do this? I am using Python 2.7.14 and Pygobject(pygi-aio-3.24.1_rev1-setup). Thank in Advance.</p>