public void SaveDiagramsAndLayout(string filename)
        {
            SaveDiagrams(filename);

            // Callback to app to save layout:
            SaveLayout.Fire(this, new FileEventArgs()
            {
                Filename = filename
            });
        }
        public void SaveDiagramsAndLayout(string filename, bool selectionOnly = false)
        {
            if (selectionOnly)
            {
                SaveSelection(filename);
            }
            else
            {
                SaveDiagrams(filename);

                // Callback to app to save layout:
                SaveLayout.Fire(this, new FileEventArgs()
                {
                    Filename = filename
                });
            }
        }