@Test
public void testProviderRefresh() throws IOException {

    TestingTools.startServer(new FakeServer(fakeKDC), grpcCleanup);
    Configuration conf = TestingTools.getBrokerConfig();
    Subject alice = fakeKDC.login(ALICE);
    UserGroupInformation.loginUserFromSubject(alice);
    AccessToken token = refresh(conf);
    assertEquals("FakeAccessToken/AuthenticatedUser=" + ALICE + ";Owner=" + ALICE + ";Target=" + MOCK_BUCKET, token.getToken());
    UserGroupInformation.setLoginUser(null);
}