Transaction

[Error Code: 1101] error caused by: 1 error occurred:
	* transaction execute failed: [Error Code: 1101] cadence runtime error: Execution failed:
  --> 6f747162ac7b8610e62b86554bab447b1945f67015617bec44285d693173bd1a:80:20
   |
80 |         let item <- self.listing.purchase(
81 |             payment: <-self.paymentVault
82 |         )
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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