Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 49febe677cd0d2c0ae133b8e56eeb6fdf6349b9ba91a8ddd10fe390a3ab15f02:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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