Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9e4a5a0ce6f740e28ce4442ecb4c6cc3da9ea659a04ba828864358ef02e4ebb9:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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