Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 67e15daa2961c398bc5027cf196adcf8eb8d7abe4a4759c0768727fb8f6d8a6b:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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