Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9b4a7debcf38b894cc1d09e0f4636b5e226cf249ef4d7f85ee9659991dd3b8d9:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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