private EnvDTE.TextSelection OpenFile()
        {
            if (firstChildItem == null)
            {
                return(null);
            }

            if (!firstChildItem.get_IsOpen(null))
            {
                EnvDTE.Window window = firstChildItem.Open(null);
                window.Visible = true;
            }
            else
            {
                firstChildItem.Document.Activate();
            }

            EnvDTE.TextSelection selection = firstChildItem.Document.Selection as EnvDTE.TextSelection;
            selection.StartOfDocument(false);

            return(selection);
        }