Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> e0f20159200da47c5a29fc94c707a8f081152ad54cfab002b8017918628c62ff:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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