title: How can I fix a "GtkDialog mapped without a transient parent" warning if my Dialog is the topmost window?
body: <p>I have a program that simply creates a GtkDialog and then calls gtk_widget_show_all on it. The GTKDialog acts as the "main window" of the program, in practice.</p>
  
  <p>Everything seems to be working alright but I get a warning from GTK saying ""GtkDialog mapped without a transient parent. This is discouraged.". How can I fix this? Do I need to create an invisible window to be the parent for my dialog?</p>