public static void ensure(boolean condition, Object... description) {
        if ( ! condition) {
            StringBuilder msg = new StringBuilder();
            for (Object part : description) {
                msg.append(part.toString());
            }
            throw new IllegalArgumentException(msg.toString());
        }
    }
Ensure the given argument is true, if not throw IllegalArgumentException
concatenating the String representation of the description arguments.
vespajlib/src/main/java/com/yahoo/protect/Validator.java