Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> fe82e980dd9e8d950e8fa0ce3d0f9b293cbf15ec75da47f6dfdf6a8164dc54b3:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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