Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9d1ffb0f6ba67ab6fc935d46bf6c14ccd030be88c9e57c00faefa435fc12b8a2:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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