Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 8cc68a70f1eae7446e90ee63f2f47620f096ed415199aec67c7f030f99a8a02d:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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