Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> f654d87681e759f306045fb762486316d5f1669827e591564407c8af12bba15d:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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