Create a singleton class in swift

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class PurchaseManager{

static let shared = PurchaseManager(productID:"PrductIdentifier",isPurchased:true)

let productID:String

private var isPurchased = false;

private init(productID:String,isPurchased:Bool){

self.productID = productID

self.isPurchased = isPurchased

}

func isViewAllowed()-> Bool{

return self.isPurchased

}

}

print("is allowed \(PurchaseManager.shared.isViewAllowed())");