Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 85db4d709a1a71a1bdf276b34ade17ea048850f9d4333fb6263d08725b30020b:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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