Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 85d4e6cee0f9effa1e12a00de2a145dbe63863c5796d63e23e4916743df2c5b1:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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