/// <summary>
        /// Shows the document in nested dock view.
        /// </summary>
        /// <param name="viewModel">The view model.</param>
        /// <param name="dockingManager">The docking manager.</param>
        /// <param name="dockingSettings">The docking settings.</param>
        /// <param name="tag">The tag.</param>
        public void ShowDocumentInNestedDockView(IViewModel viewModel, NestedDockingManager dockingManager, DockingSettings dockingSettings, object tag = null)
        {
            var document = CreateDocument(viewModel, tag);

            dockingManager.AddDockedWindow(document, dockingSettings);
        }