Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 528d8664963c25455833591b569f807051f3f4e86a0a5013ed85865bde475118:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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