Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 881ef7df2d321fa9bfc1b620e962baaf75a8ebb748bd8bbd13b1ba1d1163b730:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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