Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 1cc79d7dbc569a6e666e0320290ccb674ea7e8606ed30e6be7894b4d2b3e7f8a:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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