Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> a716979f9e0d435d5bf81de942fbccee4018d89d633a4e8aa365b68924fb3ce1:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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