Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 19aa2e28c99728e2d0434e6a3ff56998bb0c8192b1b6a9cd9358d4363d8b79f7:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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