Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 7fbe3f8910e736d34ad1d4acc83c0033dece0425f4b6ebe7ef6a95f6a3d5891a:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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