   
   /// Background NSManagedObjectContext.
   /// Returns new instance of NSManagedObjectContext each time you access this variable.
-  /// Perfect application of bacground context - asynchronous import of data into CoreData.
+  /// Use it for persisting changes to CoreData.
   public static var backgroundContext: NSManagedObjectContext {
     return CoreDuck.quack.backgroundContext
   }

  /// Save NSManagedObjectContext
  ///
  /// - Parameters:
  ///   - block: execute block of code before save
  ///   - completion: context to save
  static func saveWithBlock(_ block: @escaping (_ localContext: NSManagedObjectContext) -> Void, completion: @escaping (_ success: Bool) -> Void) {
    let backgroundContext = NSManagedObjectContext.backgroundContext
    

  /// Save NSManagedObjectContext and wait
  ///
  /// - Parameters:
  ///   - block: closure invoked before saving NSManagedObjectContext, perform changes on NSManagedObject instances here
  ///   - completion: closure that will be executed after save operation is finished
  static func saveWithBlockAndWait(_ block: @escaping (_ localContext: NSManagedObjectContext) -> Void, completion: @escaping (_ success: Bool) -> Void) {
    let backgroundContext = NSManagedObjectContext.backgroundContext
    
