private void OnSave()
        {
            var notification = new SaveFileDialogNotification();
            notification.RestoreDirectory = true;
            notification.Filter = "DGML files (*.dgml)|*.dgml";
            notification.FilterIndex = 0;
            notification.DefaultExt = ".dgml";

            SaveFileRequest.Raise(notification,
                n =>
                {
                    if (n.Confirmed)
                    {
                        Save(n.FileName);
                    }
                });
        }
        private void SaveMasks()
        {
            var notification = new SaveFileDialogNotification();
            notification.RestoreDirectory = true;
            notification.Filter = "GraphViz filter files (*.bgf)|*.bgf";
            notification.FilterIndex = 0;
            notification.DefaultExt = ".bgf";

            SaveFileRequest.Raise( notification,
                n =>
                {
                    if( n.Confirmed )
                    {
                        var module = myPresentation.GetModule<INodeMaskModule>();
                        myPersistanceService.Save( n.FileName, module.Items );
                    }
                } );
        }