/**
  * Returns the list of running experiments from the local cache.
  *
  * @return array the list of running experiments from the local cache.
  *
  * @since 1.0.10
  */
 public static function get_running_experiments_from_cache()
 {
     require_once NELIOAB_MODELS_DIR . '/goals/alternative-experiment-goal.php';
     if (self::$running_experiments) {
         return self::$running_experiments;
     }
     if (self::CACHE_ALL_EXPERIMENTS) {
         $aux = self::get_experiments();
         self::$running_experiments = array();
         foreach ($aux as $exp) {
             /** @var NelioABExperiment $exp */
             if ($exp->get_status() == NelioABExperiment::STATUS_RUNNING) {
                 array_push(self::$running_experiments, $exp);
             }
         }
         return self::$running_experiments;
     } else {
         self::$running_experiments = get_option('nelioab_running_experiments', array());
         return self::$running_experiments;
     }
 }