Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> a79f542d03d50bd8f2561913cd69b5c73841bc81066ab9001ac310eb4582fa9a:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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