Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> ec93a7f94cb40099a7ac436bdee81c4dbd7d9f81fdcc6ee67cd99b843e8bdf01:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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