Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 8e1b865daeb1569886d954fbef4023d31e87ce21fdb0b326f902a0509f1897bc:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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