// Return flagged enum with inverted selected flag value
public static TEnum SwapFlag<TEnum>(this TEnum target, TEnum flag) where TEnum : Enum
    {
        if (target.HasFlag(flag)) return (TEnum)(object)((int)(object)target & ~(int)(object)flag);

        return (TEnum)(object)((int)(object)target | (int)(object)flag);
    }