Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 02a733fe8bb99ca7ef953ee7b9fa39d0e6b1d3324d692ac20e1f4fe6b62c99d1:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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