public static AccessTokenRetriever create(Map<String, ?> configs, Map<String, Object> jaasConfig) {
        return create(configs, null, jaasConfig);
    }
@Test
    public void testConfigureRefreshingFileAccessTokenRetriever() throws Exception {
        String expected = "{}";

        File tmpDir = createTempDir("access-token");
        File accessTokenFile = createTempFile(tmpDir, "access-token-", ".json", expected);

        Map<String, ?> configs = Collections.singletonMap(SASL_OAUTHBEARER_TOKEN_ENDPOINT_URL, accessTokenFile.toURI().toString());
        Map<String, Object> jaasConfig = Collections.emptyMap();

        try (AccessTokenRetriever accessTokenRetriever = AccessTokenRetrieverFactory.create(configs, jaasConfig)) {
            accessTokenRetriever.init();
            assertEquals(expected, accessTokenRetriever.retrieve());
        }
    }