Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 40fdbfdee1c48dd080d2aaa16e25246a8669c07bd4ea9b7f5c886cc3d0f4c44b:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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