Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 7f9b3f909e4b366dd2a791fb8ddeff9aafb217ae5ccdd46b553f46f297b500aa:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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