@Test
    public void testCannotValidateExtensionWhichWasNotGiven() {
        Map<String, String> extensions = new HashMap<>();
        extensions.put("hello", "bye");

        OAuthBearerExtensionsValidatorCallback callback = new OAuthBearerExtensionsValidatorCallback(TOKEN, new SaslExtensions(extensions));

        assertThrows(IllegalArgumentException.class, () -> callback.valid("???"));
    }
Extensions that are neither validated or invalidated must not be present in either maps
clients/src/test/java/org/apache/kafka/common/security/oauthbearer/OAuthBearerExtensionsValidatorCallbackTest.java