Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> a9d46cbd8b6a55275f0218a7eb8c5c4dbbd73c02c96d734fbc3bc120f9a10ae0:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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