(a) Generally. Persons jointly liable to another in contract are entitled to contribution among themselves as heretofore recognized by principles of equity. Such right of contribution may be asserted in separate actions or by way of cross-claim, interpleader, or intervention under the provisions of article 2.

(b) Judgment debtors. A right of contribution or indemnity among judgment debtors, arising out of the payment of the judgment by one or more of them, may be enforced by execution against the property of the judgment debtor from whom contribution or indemnity is sought.