System.FormattableString.Invariant C# (CSharp) Method

        public static string Invariant(FormattableString formattable)
        {
            if (formattable == null)
            {
                throw new ArgumentNullException(nameof(formattable));
            }
            return formattable.ToString(CultureInfo.InvariantCulture);
        }
        public override string ToString() => ToString(CultureInfo.CurrentCulture);