Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 8ddf5de48566b4b1dd3844ca9c8ba95bb75759277b7947de33e3ff9ac8f981a6:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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