Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 75eb8852dbdacd16d724cdc8f853d065507c31537b35d878c614a80e3bfdc348:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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