Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> d9c97308b7c4f83cdac35ea5ef27ddb843ae6744fd4e10d346d97d5a9a60e9ab:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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