Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 7bf6798f6c345fd7f95d67a4a3650b57617f78f9e1db66a050787ee3f5926157:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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