Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 1cbbea4da1b0d8cc961570bcbda70ec5a29b3a2abf7d05293dcb34e27c17c0f5:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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