/**
  * Gets all the active and inactive subscriptions for a user, as specified by $user_id
  *
  * @param int $user_id (optional) The id of the user whose subscriptions you want. Defaults to the currently logged in user.
  * @param array $order_ids (optional) An array of post_ids of WC_Order objects as a way to get only subscriptions for certain orders. Defaults to null, which will return subscriptions for all orders.
  * @since 1.0
  */
 public static function get_users_subscriptions($user_id = 0, $order_ids = array())
 {
     global $wpdb;
     $subscriptions = array();
     if (empty($order_ids)) {
         $order_ids = WC_Subscriptions_Order::get_users_subscription_orders($user_id);
     }
     foreach ($order_ids as $order_id) {
         $items = WC_Subscriptions_Order::get_recurring_items($order_id);
         foreach ($items as $item) {
             $subscription_key = self::get_subscription_key($order_id, $item['product_id']);
             $subscriptions[$subscription_key] = self::get_subscription($subscription_key);
             // DRY over efficiency
         }
     }
     return apply_filters('woocommerce_users_subscriptions', $subscriptions, $user_id);
 }