Show last Viewpoint in Autodesk Navisworks

Using this code snippet I create a viewpoint for the current view.:

internal static Document doc = Autodesk.Navisworks.Api.Application.ActiveDocument;

        internal static void CreateViewpoint()
        {
            Viewpoint curentVievpoint = doc.CurrentViewpoint.Value;

            SavedViewpoint newViewpoint = new SavedViewpoint(curentVievpoint);
            newViewpoint.DisplayName = "_View";
            doc.SavedViewpoints.AddCopy(newViewpoint);
        }

How to pass the last saved viewpoint to "lastViewpoint"?

        internal static void GoToLastCreatedViewpoint()
        {
           Viewpoint lastViewpoint = new Viewpoint();  
           doc.CurrentViewpoint.CopyFrom(lastViewpoint);
        }

I tried to represent "lastViewpoint" as SavedViewpoint but failed.

Also this code adds redlineText to CurentViewpoint

internal static void CreateViewpoint()
    {
        Viewpoint curentVievpoint = doc.CurrentViewpoint.Value;
        SavedViewpoint newViewpoint = new SavedViewpoint(curentVievpoint);
        newViewpoint.DisplayName = "_Вид";
        doc.SavedViewpoints.AddCopy(newViewpoint);
    
        var viewpoints = doc.SavedViewpoints;
        int newIndex = viewpoints.Value.Count - 1;
        SavedViewpoint viewpointCopy = viewpoints.Value[newIndex].CreateCopy() as SavedViewpoint;
    
        Point2D point2D = new Point2D(155, 830);
        var redlineText = new LcOpRedlineText(textComment, ScreenToCameraSpace(point2D));
        redlineText.SetLineThickness(5);
        redlineText.SetLineColor(Color.White);
    
        viewpointCopy.Redlines.Add(redlineText);
        viewpoints.ReplaceWithCopy(newIndex, viewpointCopy);
    
        SavedItem item = doc.SavedViewpoints.Value[newIndex];
        SavedViewpoint savedViewpoint = item as SavedViewpoint;
        Viewpoint viewpoint = savedViewpoint.Viewpoint;
        doc.SavedViewpoints.CurrentSavedViewpoint = item;
    }