Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> ceaf1981e4e033d824e94acbe3e1bcdf6d3afef4a936f5bb9537cb26d3773010:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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