code: func setItalianLeadingZerosForPhoneNumber(
  	nationalNum string, phoneNumber *PhoneNumber) {
  	if len(nationalNum) < 2 || nationalNum[0] != '0' {
  		return
  	}
  
  	phoneNumber.ItalianLeadingZero = proto.Bool(true)
  	numLeadZeros := 1
  	// Note that if the national number is all "0"s, the last "0"
  	// is not counted as a leading zero.
  	for numLeadZeros < len(nationalNum)-1 && nationalNum[numLeadZeros] == '0' {
  		numLeadZeros++
  	}
  	if numLeadZeros != 1 {
  		phoneNumber.NumberOfLeadingZeros = proto.Int(numLeadZeros)
  	}
  }
docs: // Returns an iterable over all PhoneNumberMatch PhoneNumberMatches in text.
  // This is a shortcut for findNumbers(CharSequence, String, Leniency, long)
  // getMatcher(text, defaultRegion, Leniency.VALID, Long.MAX_VALUE)}.
  //public Iterable<PhoneNumberMatch> findNumbers(CharSequence text, String defaultRegion) {
  //    return findNumbers(text, defaultRegion, Leniency.VALID, Long.MAX_VALUE);
  //}
  // Returns an iterable over all PhoneNumberMatch PhoneNumberMatches in text.
  //public Iterable<PhoneNumberMatch> findNumbers(
  //	final CharSequence text, final String defaultRegion, final Leniency leniency,
  //	final long maxTries) {
  //
  //		return new Iterable<PhoneNumberMatch>() {
  //			public Iterator<PhoneNumberMatch> iterator() {
  //				return new PhoneNumberMatcher(
  //					PhoneNumberUtil.this, text, defaultRegion, leniency, maxTries);
  //			}
  //		};
  //	}
  // A helper function to set the values related to leading zeros in a
  // PhoneNumber.