code: func parsePrefixAsIdd(iddPattern *regexp.Regexp, number *builder.Builder) bool {
  	numStr := number.String()
  	ind := iddPattern.FindStringIndex(numStr)
  	if len(ind) == 0 || ind[0] != 0 {
  		return false
  	}
  	matchEnd := ind[1] // ind is a two element slice
  	// Only strip this if the first digit after the match is not
  	// a 0, since country calling codes cannot begin with 0.
  	find := CAPTURING_DIGIT_PATTERN.FindAllString(numStr[matchEnd:], -1)
  	if len(find) > 0 {
  		if NormalizeDigitsOnly(find[0]) == "0" {
  			return false
  		}
  	}
  
  	numBytes := []byte(numStr)
  	number.ResetWith(numBytes[matchEnd:])
  	return true
  }
docs: // Strips the IDD from the start of the number if present. Helper function
  // used by maybeStripInternationalPrefixAndNormalize.