Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> c9e8ac31455e3aef7aa39c1ecaa22d900e694817e8d3a6c0b479cff5aa61f01e:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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