internal static AppFlag? ArgStringToFlag(string arg) {
AppFlag result;
var s = string.Join("", arg.Split('-').Where(x => x.Length > 0).Select(x => (char)(x[0] + 'A' - 'a') + (x.Length > 1 ? x.Substring(1) : "")));
return Enum.TryParse(s, out result) ? result : (AppFlag?)null;
}