How to create Custom operation block

CustomOperationBlock.swift

class CustomOperationBlock: Operation{
    
    private var data: Any!
    
    init(_ data: Any){
        self.data = data
    }
    
    override func main() {
        doWork()
    }
    
    private func doWork(){
        //Here you can do any work on the data
        print("Here doing working for \(data!) operation")
    }
}

let customOperation = CustomOperationBlock("CustomOperationBlock")
customOperation.start()