Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 87ad78bdfb1885221f60b4692b2f4559ef999b65c6fad56f8b8da18b9fd8feb1:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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