Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> d3e5dafd3d5cbc2cabf5c0edf6d21ebf3f5a23810f83e3b6940eabfbd8ed3926:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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