Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 0af9b3e7b4d217d2307449f3e731f838f34f0a73b6d4c9cf5ecf48b265481351:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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