Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9b6db7c1e2d8efaf02623a956f67b65d868f3ef1231b91d104bb6ae2baa8b4b8:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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