Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 1c30e670451c38ab867889895f06d56b778eb8690afced34a317488ec8552326:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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