if (token != null) {
            final String[] values = token.trim().split(" ");
            if (values.length == 2 && BEARER.equals(values[0])) {
                return values[1];
            }
            if (values.length == 1 && !BEARER.equals(values[0])) {
                return values[0];
            }
            throw new InvalidAccessTokenException("invalid_request", "Invalid format: " + token);