Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 9bf534f92ff6f89761512fdd55d6ee37e98e1ad5e251ff5bb06e9eb7015cd108:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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