Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> af251232307099cdaab154dd28e254954beab538e40314753f142afed7771a23:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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