Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 856e7b0c9a30da42957b9972cdb56d6a36d83fb7d08654a41a84b5edc05dbb11:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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