static JInternalFrame getInternalFrame(fO _o) { ret swing(func -> JInternalFrame { O o = _o; if (o instanceof ButtonGroup) o = first(buttonsInGroup((ButtonGroup) o)); if (!(o instanceof Component)) null; Component c = (Component) o; while (c != null) { if (c instanceof JInternalFrame) return (JInternalFrame) c; c = c.getParent(); } null; }); }