Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 06d048eb5ba94c5a7bfc8bebe9c6b900f0c14f7d70442eef8bd0d18d33d78f8e:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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