Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 881320131938a92a32014a10728c14780e19115b77eb349925b2cf8657d48387:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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