public function order_has_tickets( $order_id ) {
		$has_tickets = false;

		$done = get_post_meta( $order_id, $this->order_has_tickets, true );
		/**
		 * get_post_meta returns empty string when the meta doesn't exists
		 * in support 2 possible values:
		 * - Empty string which will do the logic using WC_Order below
		 * - Cast boolean the return of the get_post_meta
		 */
		if ( '' !== $done ) {
			return (bool) $done;
		}

		// Get the items purchased in this order
		$order       = new WC_Order( $order_id );
		$order_items = $order->get_items();

		// Bail if the order is empty
		if ( empty( $order_items ) ) {
			return $has_tickets;
		}

		// Iterate over each product
		foreach ( (array) $order_items as $item_id => $item ) {
			$product_id = isset( $item['product_id'] ) ? $item['product_id'] : $item['id'];
			// Get the event this tickets is for
			$post_id = get_post_meta( $product_id, $this->event_key, true );

			if ( ! empty( $post_id ) ) {

				$has_tickets = true;
				break;
			}
		}

		return $has_tickets;
	}