Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> b4fc44bd5246a6e0e02cf1c16272a8b62877c28adcd70a9b3b1a2188cc70aa4e:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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