Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 1f1a85cc4e9e24c9c7cf1ff96fd64a5c5872015ef72509f9db3ccd7d1ae22caf:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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