public static SolutionFolder AddSolutionFolderEx(this SolutionFolder solutionFolder, string folderName)
        {
            SolutionFolder folder = solutionFolder.GetSolutionFolderEx(folderName);

            if (folder == null)
            {
                folder = solutionFolder.AddSolutionFolder(folderName).Object;
            }

            return(folder);
        }