@Override protected UserIdentity login(String username, String password) {
      if (users.containsKey(username)) {
        if (users.get(username).equals(password)) {
          return new PamUserIdentity(username);
        }
      }
      return null;
    }
TestHS2HttpServerPam -- executes tests of HiveServer2 HTTP Server for Pam authentication
service/src/test/org/apache/hive/service/server/TestHS2HttpServerPam.java