Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6ef31b04cd7417064396627413021951780251f525b1dae3dbd446ba711ac1b0:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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