Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 16e5f2b57176abe1f81cb5553bf73dfa62d42ee8e7c6e634985a007872b3c391:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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