Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> b872dc4b52d02517afd4f1e3f0f66f0f7273d66a6aecb5af1ef1c0e1ca71c0f8:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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