     self.handler = changeHandler
     _ = self.observer
   }
-
+  
   // MARK: - Private implementation
-
+  
   /// Processes the incoming notification.
   private func handleChanges<C: ManagedObjectContextChange>(_ changes: C, for event: NSManagedObjectContext.ObservableEvents, in context: NSManagedObjectContext) {
     func process(_ value: Set<NSManagedObject>) -> Set<T> {

  ///   - notificationCenter: The `NotificationCenter` listening the the `NSManagedObjectContext` notifications.
  ///   - The operation queue to which block should be added. If you pass nil, the block is run synchronously on the posting thread.
  ///   - changeHandler: The completion handler.
  init(context: NSManagedObjectContext,
       event: NSManagedObjectContext.ObservableEvents,
       observeSubEntities: Bool = false,
       queue: OperationQueue? = nil,
       changeHandler: @escaping (AnyManagedObjectContextChange<T>, NSManagedObjectContext.ObservableEvents) -> Void) {
    self.managedObjectContext = context
    self.event = event
    self.observeSubEntities = observeSubEntities

  ///
  /// The observed event.
  public let event: NSManagedObjectContext.ObservableEvents
  
  /// **CoreDataPlus**
  ///
  /// If `true`, all the changes happening in the subentities will be observed.
  public let observeSubEntities: Bool
  
  /// **CoreDataPlus**
  ///
  /// The observed entity.
