 #endif
 #endif
 
-open class Operation: NSObject {
+open class Operation : NSObject {
     let lock = NSLock()
     internal weak var _queue: OperationQueue?
     internal var _cancelled = false

    static let OperationQueueKey = DispatchSpecificKey<Unmanaged<OperationQueue>>()
#endif

    open class func currentQueue() -> OperationQueue? {
#if DEPLOYMENT_ENABLE_LIBDISPATCH
        let specific = DispatchQueue.getSpecific(key: OperationQueue.OperationQueueKey)
        if specific == nil {

        lock.unlock()
    }
    
    open func addOperation(_ block: @escaping () -> Swift.Void) {
        let op = BlockOperation(block: block)
        op.qualityOfService = qualityOfService
        addOperation(op)
