private static String stripBearerTokenPrefix(String rawValue) {
        String stripped = rawValue.strip();
        String prefixRemoved = stripped.startsWith(BEARER_TOKEN_PREFIX)
                ? stripped.substring(BEARER_TOKEN_PREFIX.length()).strip()
                : stripped;
        if (prefixRemoved.isBlank()) {
            throw new IllegalArgumentException(String.format("Access token is blank: '%s'", prefixRemoved));
        }
        return prefixRemoved;
    }
Represents an Athenz Access Token

@author bjorncs
vespa-athenz/src/main/java/com/yahoo/vespa/athenz/api/AthenzAccessToken.java