added a new function getExistingListingIDs to Storefront resource that allows the owner to check for existing listings of an NFT resource. useful to make sure only a single listing exists for an NFT. The method is not added to StorefrontPublic due to backward incompatibility concerns, so this won't be publicly accessible.
added a new function
getExistingListingIDsto Storefront resource that allows the owner to check for existing listings of an NFT resource. useful to make sure only a single listing exists for an NFT. The method is not added toStorefrontPublicdue to backward incompatibility concerns, so this won't be publicly accessible.