protected static function getService($url, $banExpression)
 {
     // prepare API call
     $service = new RestfulService($url, 0);
     // set basic auth
     $username = Config::inst()->get('SectionIO', 'username');
     $password = Config::inst()->get('SectionIO', 'password');
     $service->basicAuth($username, $password);
     // set query string (ban expression)
     $service->setQueryString(array('banExpression' => $banExpression));
     return $service;
 }