private void createServer(SecurityProtocol securityProtocol, String saslMechanism,
            boolean enableSaslAuthenticateHeader) throws Exception {
        if (enableSaslAuthenticateHeader)
            server = createEchoServer(securityProtocol);
        else
            server = startServerWithoutSaslAuthenticateHeader(securityProtocol, saslMechanism);
        updateScramCredentialCache(TestJaasConfig.USERNAME, TestJaasConfig.PASSWORD);
    }
Tests OAUTHBEARER fails the connection when the client presents a token with
insufficient scope .
clients/src/test/java/org/apache/kafka/common/security/authenticator/SaslAuthenticatorTest.java