Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 85f71cca98636083674d02f0ee1f90488eb85b85c86af1a43ef9449858347035:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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