Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6c890e9f46850287ccb4de1cbf40a1dd095bc75f7fa993e7048de7872e3ccbb2:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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