Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6e448ba3aa91b830efd0bbc95f74bcf952dd309fb91e70d86acbea69a3ed41a0:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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