Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 3427f9fd479fc3b0aac0811c2f53d72f0b2a6c9a7a76f130ad89127799da2e3f:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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