Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> b550b0de58baa422cf6574e0cbbdfb34bfbf3d837664d614866b936afdbbe647:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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