Parasite and GtkEmpty

[Gerald Nunn]

I'm using Gtk Parasite with the awf-gtk3 application (Another Widget Factory) to sort out some issues with a theme and I'm noticing when I click certain parts of the application parasite shows it as GtkEmpty. Is this actually a GTK widget because googling doesn't show much or is it simply a placeholder? Also, would this have specific CSS classes associated with it or is getting it's color from the background widget, in this case a GTKBox?