Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> ff9920588a6d7e2d35aecef4fff5cfe0f0a27b845e74491e099534b1bd5c3e03:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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