> Test ()     {         IEnumerable<String> lexicalStrings = new List<String> { "test", "t" };         IEnumerable<String> allLexicals = new List<String> { "test", "Test", "T", "t" };          IEnumerable<String> lexicals = new List<String> ();         foreach (String s in lexicalStrings)             lexicals = lexicals.Union (allLexicals.Where (lexical => lexical