Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> d2865435a1fc6c0f2cfca7ba31bd8a7c57b7f4a061319bf4d91fa4f3b77fdd40:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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