Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 67b67cb7e9b2c73adf24fa9b95fbae84d2ff75068fcc986ac620f83e6db4a01d:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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