Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> f8015ef7530eb54c50f45c0bdb34f82d123a9e5555dd1e9cb9fb5d0fd8f7ed53:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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