Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> 6be693cfa8d93417626a1a9dd7f74fd1212eb45485da1cee1fcbc34cb01e5bc8:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

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