     
     /// Underlying `Foundation.OperationQueue` instance used for executing
     /// `Foundation.Operation` operations
-    public let operationQueue: OperationQueue
+    internal let operationQueue: OperationQueue
     
     /**
      Returns queue associated with application main queue.

        dependency.enqueue()
    }
}

     - Parameter task: Task<T> to be added
     */
    open func add<T>(task: Task<T>) {
        if !task.contains(observer: FinishBlockObserver.self) {
            task.add(observer: FinishBlockObserver { [weak self] in
                if let queue = self {
                    queue.delegate?.didFinish(task: task, inQueue: queue)
                }
            })
        }
        
        // Evaluate condition dependencies and add them to the queue
