setCountryCode method
set country code
length of value
is 2.
Implementation
setCountryCode(String? value) {
if (value != null) {
if (value.length != 2) {
throw ValueLengthErr(title: "countryCode", length: "2");
}
var countryCode = setTLV(value, ID.countryCode);
this.value = this.value.copyWith(countryCode: countryCode);
}
}