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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _attempt_to_format_accrued_digits(self):
 """Checks to see if there is an exact pattern match for these digits. If so, we should use this instead of any other formatting template whose leadingDigitsPattern also matches the input. """

        for number_format in self._possible_formats:
            num_re = re.compile(number_format.pattern)
            if fullmatch(num_re, self._national_number):
                if number_format.national_prefix_formatting_rule is None:
                    self._should_add_space_after_national_prefix = False
                else:
                    self._should_add_space_after_national_prefix = bool(_NATIONAL_PREFIX_SEPARATORS_PATTERN.search(number_format.national_prefix_formatting_rule))
                formatted_number = re.sub(num_re, number_format.format, self._national_number)
                return self._append_national_number(formatted_number)
        return U_EMPTY_STRING