A service provider can rely on a debtor/creditor as security for its claim. This type of lien, conferred by virtue of an agreement between the creditor and the debtor, is a sub-species of a broader right to retain physical control of another’s property, whether movable or immovable, as a mechanism for securing payment of a claim, until the claim has been met. In other words, the service provider, who makes provision for such a lien in its contract, can refuse to release goods which are in its possession until it has received payment.