Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 849f1cb3b3e191c01b35b914181bb796c796b6bcc619713e790d258b8d76cfb2:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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