code:   public void init(Map<String,Object> pluginConfig) {
      try {
        String delegationTokenEnabled = (String)pluginConfig.getOrDefault(DELEGATION_TOKEN_ENABLED_PROPERTY, "false");
        authFilter = (Boolean.parseBoolean(delegationTokenEnabled)) ? new HadoopAuthFilter() : new AuthenticationFilter();
  
        // Initialize kerberos before initializing curator instance.
        boolean initKerberosZk = Boolean.parseBoolean((String)pluginConfig.getOrDefault(INIT_KERBEROS_ZK, "false"));
        if (initKerberosZk) {
          (new Krb5HttpClientBuilder()).getBuilder();
        }
  
        FilterConfig conf = getInitFilterConfig(pluginConfig);
        authFilter.init(conf);
  
      } catch (ServletException e) {
        log.error("Error initializing " + getClass().getSimpleName(), e);
        throw new SolrException(ErrorCode.SERVER_ERROR, "Error initializing " + getClass().getName() + ": "+e);
      }
    }
  
    @SuppressWarnings("unchecked")
  