Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> f0662e9ea64457e05a0b6ac8b33f16f78bf07ec4e73fd2a49950ceb9f6b2a2d4:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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