code: @CliObjectOption(description = "Authenticate using kerberos. Format: \"<login-user>:<keytab-file>\".")
    public EmbeddedGobblin kerberosAuthentication(String credentials) {
      List<String> split = Splitter.on(":").splitToList(credentials);
      if (split.size() != 2) {
        throw new RuntimeException("Cannot parse " + credentials + ". Expected <login-user>:<keytab-file>");
      }
      try {
        usePlugin(PluginStaticKeys.HADOOP_LOGIN_FROM_KEYTAB_ALIAS);
      } catch (ReflectiveOperationException roe) {
        throw new RuntimeException(String.format("Could not instantiate %s. Make sure gobblin-runtime-hadoop is in your classpath.",
            PluginStaticKeys.HADOOP_LOGIN_FROM_KEYTAB_ALIAS), roe);
      }
      sysConfig(PluginStaticKeys.LOGIN_USER_FULL_KEY, split.get(0));
      sysConfig(PluginStaticKeys.LOGIN_USER_KEYTAB_FILE_FULL_KEY, split.get(1));
      return this;
    }
docs: Load Kerberos keytab for authentication. Crendetials format "<login-user>:<keytab-file>".