Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9f5593c4fd057feabce55b47a8eacedd31935a5a9c968745f13358ca46d4969b:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

error: pre-condition failed: listing has already been purchased
   --> 4eb8a10cb9f87357.NFTStorefront:243:16