Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 421ca022ff39c716bbadd697e4b9c589381c23aa5e4f24e3fd1d8136cc4ee761:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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