Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 89613afb7753cec7f4e1b2e085479d15bbb92115ac195c70ed3315ff33b8f16d:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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