Child Support Arrears Sold As An Annuity For A 3rd Party

Say you are owed $20,000 from the non-custodial parent for previous non-payment of child support and the judge enters an order for regular payments plus an additional amount to go towards satisfying the arrears. Unless you waive the arrears out of the goodness of your heart, this is a guaranteed debt owed to you, right? Aside from sitting by for the next 70 years collecting $10 at a time, is it possible or even legal to 'sell' that 'annuity' to a third party for a lump sum? Every day I see advertisements from firms who purchase recurring payments from people who have been awarded money by the courts from such things like accident insurance or other guaranteed annuities, so I wonder: is it possible to work out some similar arrangement regarding child support arrears?