Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 4a22fdbc0d6ce2fcd3801a2d14a9ac86ff0e7624cd39de43d41411ad92d9000b:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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