Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> d478e94f8b0e8c9c4592e6500fe5e1a2c4f16d1a81a71f3435d0061a14de6fc2:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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