Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6e6ae00e39ddad0aed6279646fc20ffda18c7e43d8d2dac7c8feb1bfba9b1a3d:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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