Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6387b1b9a54b62bcd9c6b71a33ef7fd841c6008e36cd13d406080c85314d648f:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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