Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 277f66972eb0db2aa3777c1cfdd9ee8d0e552fcad73919eadcfd2b1fd9d8690e:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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