Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> da8c13669214d97165f37c9570e4939c6f0957463429469fe0859b0c45772f45:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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