Transaction

[Error Code: 1101] error caused by: 1 error occurred:
	* transaction execute failed: [Error Code: 1101] cadence runtime error: Execution failed:
  --> 20726e8dcfc737a936d45528da8a20d819ab0cca274ecae46badbc5fdde22007:80:20
   |
80 |         let item <- self.listing.purchase(
81 |             payment: <-self.paymentVault
82 |         )
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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