Desrialize a page setup from an a{sv} variant.
The variant must be in the format produced by [method@Gtk.PageSetup.to_gvariant].
an a{sv} GVariant
a new GtkPageSetup object
ConstructionException GTK+ fails to create the object.
See Implementation
Desrialize a page setup from an a{sv} variant.
The variant must be in the format produced by [method@Gtk.PageSetup.to_gvariant].