Gtk.PageSetup.prototype.set_paper_size

function set_paper_size(size:Gtk.PaperSize):void {
    // Gjs wrapper for gtk_page_setup_set_paper_size()
}

Sets the paper size of the Gtk.PageSetup without changing the margins. See Gtk.set_paper_size_and_default_margins.

Since 2.10

size

a Gtk.PaperSize