Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 94a35ed0875b3c18ef0a1d06595a6b4c253d1170aed6e4039b4d2a9f0f7ea2f8:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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