Gtk.Container.prototype.set_focus_chain

function set_focus_chain(focusable_widgets:[Gtk.Widget]):void {
    // Gjs wrapper for gtk_container_set_focus_chain()
}

Sets a focus chain, overriding the one computed automatically by GTK+.

In principle each widget in the chain should be a descendant of the container, but this is not enforced by this method, since it's allowed to set the focus chain before you pack the widgets, or have a widget in the chain that isn't always packed. The necessary checks are done when the focus chain is actually traversed.