class AsyncOperation : NSOperation {
    override func main () {
        print("In the user queue")
        NSOperationQueue.mainQueue().addOperationWithBlock({
            print("main block")
        })
    }
}
let queue = NSOperationQueue()
let operation = AsyncOperation();
queue.addOperation(operation)
it prints In the user queue but does not print main block . Since I am adding to the main queue I expect it to get executed. Do i have to start the queue execution ??
