code: def _attempt_to_extract_idd(self):
          
          international_prefix = re.compile(unicod("\\") + _PLUS_SIGN + unicod("|") +
                                            (self._current_metadata.international_prefix or U_EMPTY_STRING))
          idd_match = international_prefix.match(self._accrued_input_without_formatting)
          if idd_match:
              self._is_complete_number = True
              start_of_country_calling_code = idd_match.end()
              self._national_number = self._accrued_input_without_formatting[start_of_country_calling_code:]
              self._prefix_before_national_number = self._accrued_input_without_formatting[:start_of_country_calling_code]
              if self._accrued_input_without_formatting[0] != _PLUS_SIGN:
                  self._prefix_before_national_number += _SEPARATOR_BEFORE_NATIONAL_NUMBER
              return True
          return False
docs: Extracts IDD and plus sign to self._prefix_before_national_number
          when they are available, and places the remaining input into
          _national_number.
  
          Returns True when accrued_input_without_formatting begins with the plus sign or valid IDD for
          default_country.