Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 93c12a434ca021a39bd21df76f2b8953714d6158b80a06fd9db0dbd96c9db454:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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