Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6136cb54118e02baaf18c79fe62868f9fa0810369cccb5ffda9ff36b6a821e05:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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