Gtk.RadioButton.new_from_widget

function new_from_widget(radio_group_member:Gtk.RadioButton):Gtk.Widget {
    // Gjs wrapper for gtk_radio_button_new_from_widget()
}

Creates a new Gtk.RadioButton, adding it to the same group as radio_group_member. As with Gtk.RadioButton.new, a widget should be packed into the radio button.

radio_group_member: an existing Gtk.RadioButton.
Returns: a new radio button.