/**
* Returns the number of failed payments for a given subscription.
*
* @param $order WC_Order The WC_Order object of the order for which you want to determine the number of failed payments.
* @param product_id int The ID of the subscription product.
* @return string The key representing the given subscription.
* @since 1.0
*/
public static function get_failed_payment_count($order, $product_id)
{
$failed_payment_count = WC_Subscriptions_Manager::get_subscriptions_failed_payment_count($order->customer_user, WC_Subscriptions_Manager::get_subscription_key($order->id, $product_id));
return $failed_payment_count;
}
