     /// - `context` : optional MOC.  If nothing is passed, mainContext is assumed.
     /// - `completion` : optional completion block. Called on the main queue.
     
-    public func saveToDisk(context: NSManagedObjectContext? = nil, completion: ErrorCompletionBlock? = nil) {
+    public func saveToDisk(context: NSManagedObjectContext? = nil, completion: ((error: ErrorType?) -> Void)? = nil) {
         guard deletedStore else {
             completion?(error: CoreDataStackError.DeletedStore)
             return

/// ><><><><><><><
public extension CoreDataStack {

    
    
    ///Tears down the stack by removing and niling the current persistentStoreCoordinator, niling the
    ///managedObjectModel and resets the writing and main contexts in a thread-safe manner. Subsequently,

extension CoreDataStack {
    
    //Convenience for dispatching back on the main queue
    private func onMain(withError error: ErrorType? = nil, call completion: ((error: ErrorType?) -> Void)?)  {
        dispatch_async(dispatch_get_main_queue()) {
            completion?(error: error)
        }
