Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6101f91bec2f71c2f1ef646b08796b7024d199b7805786a9e3281754f3248a35:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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