Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 81e62d5f0f2a440348bbf35f6598f7ef4c08203af2e6fd71c9b508a63f976eb5:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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