Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> f30a77cfc85428b86efb3e0480eddc30f0fe954852154123a4c8cfcd7ce63816:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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