PhoneNumbers.NumberFormat.Builder.SetNationalPrefixFormattingRule C# (CSharp) Method

            public Builder SetNationalPrefixFormattingRule(string value)
            {
                if(value == null) throw new global::System.ArgumentNullException("value");
                result.hasNationalPrefixFormattingRule = true;
                result.nationalPrefixFormattingRule_ = value;
                return this;
            }

        /**
        *  Extracts the available formats from the provided DOM element. If it does not contain any
        *  nationalPrefixFormattingRule, the one passed-in is retained. The nationalPrefix,
        *  nationalPrefixFormattingRule and nationalPrefixOptionalWhenFormatting values are provided from
        *  the parent (territory) element.
        */
        public static void LoadAvailableFormats(PhoneMetadata.Builder metadata,
            XElement element, string nationalPrefix,
            string nationalPrefixFormattingRule,
            bool nationalPrefixOptionalWhenFormatting)
        {
            var carrierCodeFormattingRule = "";
            if (element.HasAttribute(CARRIER_CODE_FORMATTING_RULE))
                carrierCodeFormattingRule = ValidateRE(
                    GetDomesticCarrierCodeFormattingRuleFromElement(element, nationalPrefix));
            var numberFormatElements = element.GetElementsByTagName(NUMBER_FORMAT).ToList();
            var hasExplicitIntlFormatDefined = false;

            var numOfFormatElements = numberFormatElements.Count;
            if (numOfFormatElements > 0)
            {
                foreach (var numberFormatElement in numberFormatElements)
                {
                    var format = new NumberFormat.Builder();

                    if (numberFormatElement.HasAttribute(NATIONAL_PREFIX_FORMATTING_RULE))
                    {
                        format.SetNationalPrefixFormattingRule(
                            GetNationalPrefixFormattingRuleFromElement(numberFormatElement, nationalPrefix));
                        format.SetNationalPrefixOptionalWhenFormatting(
                            numberFormatElement.HasAttribute(NATIONAL_PREFIX_OPTIONAL_WHEN_FORMATTING));
                    }
                    else
                    {
                        format.SetNationalPrefixFormattingRule(nationalPrefixFormattingRule);
                        format.SetNationalPrefixOptionalWhenFormatting(nationalPrefixOptionalWhenFormatting);
                    }
                    if (numberFormatElement.HasAttribute("carrierCodeFormattingRule"))
                        format.SetDomesticCarrierCodeFormattingRule(ValidateRE(
                            GetDomesticCarrierCodeFormattingRuleFromElement(
                                numberFormatElement, nationalPrefix)));
                    else
                        format.SetDomesticCarrierCodeFormattingRule(carrierCodeFormattingRule);

                    // Extract the pattern for the national format.
                    var nationalFormat =
                        LoadNationalFormat(metadata, numberFormatElement, format);
                    metadata.AddNumberFormat(format);

                    if (LoadInternationalFormat(metadata, numberFormatElement, nationalFormat))
                        hasExplicitIntlFormatDefined = true;
                }
                // Only a small number of regions need to specify the intlFormats in the xml. For the majority
                // of countries the intlNumberFormat metadata is an exact copy of the national NumberFormat
                // metadata. To minimize the size of the metadata file, we only keep intlNumberFormats that
                // actually differ in some way to the national formats.
                if (!hasExplicitIntlFormatDefined)
                    metadata.ClearIntlNumberFormat();
            }
        }