Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> ae485170ec252864f109c036994970ab2f468ca6c01a3f1615e66307053448ab:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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