Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 21ff4b09f1899e234d50eb1d00f2fc17234dc3aa4e38461421e7653c619a396e:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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