private String commaPrependedStringNumberAndListClaimsJsonText() throws OAuthBearerConfigException {
        StringBuilder sb = new StringBuilder();
        for (String key : moduleOptions.keySet()) {
            if (key.startsWith(STRING_CLAIM_PREFIX) && key.length() > STRING_CLAIM_PREFIX.length())
                sb.append(',').append(claimOrHeaderJsonText(
                        confirmNotReservedClaimName(key.substring(STRING_CLAIM_PREFIX.length())), optionValue(key)));
            else if (key.startsWith(NUMBER_CLAIM_PREFIX) && key.length() > NUMBER_CLAIM_PREFIX.length())
                sb.append(',')
                        .append(claimOrHeaderJsonText(
                                confirmNotReservedClaimName(key.substring(NUMBER_CLAIM_PREFIX.length())),
                                Double.valueOf(optionValue(key))));
            else if (key.startsWith(LIST_CLAIM_PREFIX) && key.length() > LIST_CLAIM_PREFIX.length())
                sb.append(',')
                        .append(claimOrHeaderJsonArrayText(
                                confirmNotReservedClaimName(key.substring(LIST_CLAIM_PREFIX.length())),
                                listJsonText(optionValue(key))));
        }
        return sb.toString();
    }
Add and validate all the configured extensions.
 Token keys, apart from passing regex validation, must not be equal to the reserved key {@link OAuthBearerClientInitialResponse#AUTH_KEY}
clients/src/main/java/org/apache/kafka/common/security/oauthbearer/internals/unsecured/OAuthBearerUnsecuredLoginCallbackHandler.java