Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> e9e720c72195da797db1d744ee2a2d32b43340948743cb369e7f439de7518838:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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