Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> d0e2c086bd8cd2e58af6984a0085afbf93ceb51ec3e2b2fba9b909fe0a70cd4a:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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