private bool GetShowIntroFlag ()
        {
            var reader = XmlReader.Create (pathIntro);

            reader.MoveToContent ();

            while (reader.Read ())
            {
                if (reader.NodeType == XmlNodeType.Element &&
                    reader.Name == "noShowIntro")
                {
                    _ = reader.Read ();

                    if (reader.NodeType == XmlNodeType.Text)
                    {
                        switch (reader.Value.ToLower ())
                        {
                            case "false":
                                return false;
                            case "true":
                                return true;
                            default:
                                throw new FileFormatException 
                                    (string.Format 
                                        ($"Unknown noShowIntro value {reader.Value.ToLower ()}"));
                        } // switch
                    } // if text
                } // if noShowIntro element
            } // while

            reader.Close ();
            reader.Dispose ();
            return false;

        } // method GetShowIntroFlag