Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> fda4f7f9f8a2fe9dc6d781b23426f6c6fbff6f5f9c71d9d4851aa1550005c396:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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