public static class DefaultExceptionHandler implements IExceptionHandler {
    public List<Object> handleException(ParameterException ex, PrintStream out, Help.Ansi ansi, String... args) {
        if (ex instanceof MissingParameterException) {
            MissingParameterException missingParameterException = (MissingParameterException) ex;

            out.println("Missing parameters: " + missingParameterException.getMissingFields());
        } else if (ex instanceof UnmatchedArgumentException) {
            out.println("Unknown parameters:" + ex.getCommandLine().getUnmatchedArguments());
        } else {
            out.println(ex.getMessage());
        }

        return Collections.emptyList();
    }
}