public function __construct(SiteApplication $app, $shortname = null)
 {
     parent::__construct($app, $shortname);
     $this->client = new MailChimpAPI($this->getApiKey());
     $this->client->useSecure(true);
     // by default if the connection takes longer than 1s timeout. This will
     // prevent users from waiting too long when MailChimp is down - requests
     // will just get queued. Without setting this, the default timeout is
     // 300 seconds
     $this->client->setTimeout($app->config->deliverance->list_connection_timeout);
     if ($this->shortname === null) {
         $this->shortname = $app->config->mail_chimp->default_list;
     }
     $this->initListMergeArrayMap();
     // default double_opt_in to the config var.
     $this->double_opt_in = $this->app->config->mail_chimp->double_opt_in;
 }