Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9cf9ab58beeda15d5a21828b6bc5070b715e3d4afbf6c3cd1bcb0fd8bc9a9357:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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