private String escape(String jsonStringValue) {
        String replace1 = DOUBLEQUOTE.matcher(jsonStringValue).replaceAll(Matcher.quoteReplacement("\\\""));
        return BACKSLASH.matcher(replace1).replaceAll(Matcher.quoteReplacement("\\\\"));
    }
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