Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 29d813834ce3746a4e9aaa5074e9ac2d76fe3cd3a2fcc3e452c44de54f54f28d:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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