Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9ef3c3aed60d793ccd9ac15de5562a5af15f08d942aa06d30e1b34a2ff63b0ee:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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