Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9cff61ea7dc65a8337617d7a2cbb4d49f9a8f20e512b2e4b0adee68e36e9ced3:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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