Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9109ec8fd53bf78b506a7fe1bc83b8f5e649d4fd299d848e6e9cd4346caffa41:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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