@Test
public void testNoHostsForUsers() throws Exception {

  Configuration conf = new Configuration(false);
  conf.set("y." + REAL_USER_NAME + ".users",
    StringUtils.join(",", Arrays.asList(AUTHORIZED_PROXY_USER_NAME)));
  ProxyUsers.refreshSuperUserGroupsConfiguration(conf, "y");
  UserGroupInformation realUserUgi = UserGroupInformation
    .createRemoteUser(REAL_USER_NAME);
  UserGroupInformation proxyUserUgi = UserGroupInformation.createProxyUserForTesting(
    AUTHORIZED_PROXY_USER_NAME, realUserUgi, GROUP_NAMES);
  // IP doesn't matter
  assertNotAuthorized(proxyUserUgi, "1.2.3.4");
}