ExceptionHandlerAssistant assistant = null;
if (value instanceof ExceptionHandlerAssistant) {
assistant = (ExceptionHandlerAssistant) value;
// in case the assistant changes the context
List context = Arrays.asList(exceptionContext);
page = assistant.handleRequestException(exception, context);
exceptionContext = context.toArray();
}
else if (!(value instanceof Class)) {
renderException(exception);
return;