Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 4fd14c54bfbd70827abe85f6fdcc31bc23958dd4a09e3b66b50ce2b2b7362d6d:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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