Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> ed2a9c2ffd91b049e11ee9af2c53eaa94b5b9e1cf5e3ce87e72294e0c2b4e7b1:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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