Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 4e448cabb824889ac70a3d9f67ec9415470cbac019453860eb14d1dbe8450ff0:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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