Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 77f49fbfcf11fda5cb15e8a1d4c1736488acb476429e4843ef2b4437f84e29b0:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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