public static AccessTokenRetriever create(Map<String, ?> configs, Map<String, Object> jaasConfig) {
        return create(configs, null, jaasConfig);
    }
@Test
    public void testConfigureRefreshingFileAccessTokenRetrieverWithInvalidFile() throws Exception {
        // Should fail because the while the parent path exists, the file itself doesn't.
        File tmpDir = createTempDir("this-directory-does-exist");
        File accessTokenFile = new File(tmpDir, "this-file-does-not-exist.json");
        Map<String, ?> configs = getSaslConfigs(SASL_OAUTHBEARER_TOKEN_ENDPOINT_URL, accessTokenFile.toURI().toString());
        Map<String, Object> jaasConfig = Collections.emptyMap();
        assertThrowsWithMessage(ConfigException.class, () -> AccessTokenRetrieverFactory.create(configs, jaasConfig), "that doesn't exist");
    }