 	* @param        completion: (success: Bool, error: NSError?) -> ())
 	*/
 	public func save(completion: (success: Bool, error: NSError?) -> ()) {
-		managedObjectContext.performBlockAndWait {[weak self] in
+		managedObjectContext.performBlockAndWait { [weak self] in
 			if !self!.managedObjectContext.hasChanges {
 				completion(success: true, error: nil)
 				return

		var error: NSError?
		var nodes: Array<AnyObject> = Array<AnyObject>()
		
		managedObjectContext.performBlockAndWait {[weak self] in
			if let result: Array<AnyObject> = self!.managedObjectContext.executeFetchRequest(request, error: &error) {
				assert(nil == error, "[GraphKit Error: Fecthing nodes.]")
				for item: AnyObject in result {

			static var onceToken: dispatch_once_t = 0
			static var managedObjectContext: NSManagedObjectContext!
		}
		dispatch_once(&GKGraphManagedObjectContext.onceToken) { [weak self] in
			GKGraphManagedObjectContext.managedObjectContext = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
			GKGraphManagedObjectContext.managedObjectContext.persistentStoreCoordinator = self!.persistentStoreCoordinator
		}
