Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> bbe6a3e4a7cbb6d3b0b42bfc711ef61b06a4850863959fb3ac55b5c7eb54d577:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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