Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> ec6b36ad01059923e6499ac4ad936d8ae0afb2870b03b5bc4829c4fa3eb6e59b:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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