Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 474d4ded8bd4d9e1c7b49f50bf73b71652c09315c71e2e3f6cdfeeb43b16a37e:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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