Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 8d2c2ee5fec592ad3b6f7b2de9fb8a5c7d0adfa5673fe94dce0aa5f00897d20f:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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