Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6d75b84b0ba999b3f8c98cd1d72cbeec2edd48346c14bca5422c27b7ef15a8ef:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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