Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 78c512f6826800ff941b036c5221da98226ca7ff54b2dc7ee832dea894df3626:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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