 
     let networkActivityIndicator: NetworkActivityIndicatorInterface
 
+    /// Initializer takes no parameters.
     public convenience init() {
         self.init(indicator: UIApplication.sharedApplication())
     }


import UIKit

public protocol NetworkActivityIndicatorInterface {
    var networkActivityIndicatorVisible: Bool { get set }
}


        networkActivityIndicator = indicator
    }

    /// Conforms to `OperationObserver`, will start the network activity indicator.
    public func operationDidStart(operation: Operation) {
        dispatch_async(Queue.Main.queue) {
            NetworkIndicatorController.sharedInstance.networkActivityIndicator = self.networkActivityIndicator
