/// <summary> /// Retrieves tracked shapes from the slide metadata, finds out which shapes have been deleted by the user, /// and returns the names of those deleted shapes. /// </summary> private static List<string> RetrieveTrackedDeletions(PowerPointSlide slide) { var retrievedNameList = Common.UnserializeCollection(slide.RetrieveDataFromNotes()); if (retrievedNameList == null) return new List<string>(); var currentNames = slide.GetNameToShapeDictionary(); return retrievedNameList.Where(name => !currentNames.ContainsKey(name)).ToList(); }