/**
  * Empty the cache
  */
 public static function clear()
 {
     self::$cache = array();
 }
 /**
  * Empty the cache
  * @param mixed $dummy When method is used in add_filter()
  * @return mixed
  */
 public static function clear($dummy = null)
 {
     self::$cache = array();
     /**
      * This method is used in add_filter() so to not break anything return filter value
      */
     return $dummy;
 }