private static Cassandra.Client createThriftClient(
     String host, int port, String user, String passwd, ITransportFactory transportFactory)
     throws Exception {
   TTransport trans = transportFactory.openTransport(host, port);
   TProtocol protocol = new TBinaryProtocol(trans);
   Cassandra.Client client = new Cassandra.Client(protocol);
   if (user != null && passwd != null) {
     Map<String, String> credentials = new HashMap<>();
     credentials.put(IAuthenticator.USERNAME_KEY, user);
     credentials.put(IAuthenticator.PASSWORD_KEY, passwd);
     AuthenticationRequest authenticationRequest = new AuthenticationRequest(credentials);
     client.login(authenticationRequest);
   }
   return client;
 }