Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 31fa903230cc7d4a7fd1be0e48fe6d31ce93f950273387f164375ccf39991ceb:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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