private static void setupMockServer() throws Exception {
    MOCK_JWKS_SERVER.stubFor(get("/jwks")
        .willReturn(ok()
            .withBody(Files.readAllBytes(jwtVerificationJWKSFile.toPath()))));
    MetastoreConf.setVar(conf, ConfVars.THRIFT_METASTORE_AUTHENTICATION_JWT_JWKS_URL,
        "http://localhost:" + MOCK_JWKS_SERVER_PORT + "/jwks");
  }
This is a hack to make environment variables modifiable.
Ref: https://stackoverflow.com/questions/318239/how-do-i-set-environment-variables-from-java.
standalone-metastore/metastore-server/src/test/java/org/apache/hadoop/hive/metastore/TestRemoteHiveMetastoreWithHttpJwt.java