Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 60ab430b4e0236bb0d8b6ae5001c32b02b4619d0c4b65d2ef4294d6fed2200b7:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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