Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> a78d2cfe8d5fff166153e20c1153a45967203e4dbd6a6c46cbcd38efa78ddf92:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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