public static function control_requirement()
 {
     // If Events Managers is not installed
     if (@strlen(EM_DIR) <= 0) {
         ESS_Elements::get_events_manager_required();
     }
     // If PHP cURL not installed
     if (function_exists('curl_version') == FALSE) {
         ESS_Elements::get_php_curl_required();
     }
 }