void (DomElement element, String msg) { if (element instanceof DomFileElementImpl) { final String s = ((DomFileElementImpl<?>)element).checkValidity(); if (s != null) { throw new AssertionError(s); } return; } final DomInvocationHandler handler = DomManagerImpl.getDomInvocationHandler(element); assert handler != null; try { handler.assertValid(); } catch (AssertionError e) { throw new AssertionError(msg + e.getMessage()); } }