How to use the num2words.utils.get_digits function in num2words

raise NotImplementedError()

    if n == 0:
        return ZERO[0]

    words = []

    chunks = list(splitbyx(str(n), 3))
    i = len(chunks)
    for x in chunks:
        i -= 1

        if x == 0:
            continue

        n1, n2, n3 = get_digits(x)

        if n3 > 0:
            if n3 <= 2:
                words.append(HUNDRED[n3][0])
            else:
                words.append(ONES[n3][0])
                words.append(HUNDRED[3][0])

        if n2 > 1:
            words.append(TWENTIES[n2][0])

        if n2 == 1:
            words.append(TENS[n1][0])
        elif n1 > 0 and not (i > 0 and x == 1):
            words.append(ONES[n1][0])

def _int2word(self, n, feminine=False):
        if n == 0:
            return ZERO[0]

        words = []
        chunks = list(splitbyx(str(n), 3))
        i = len(chunks)

        for x in chunks:
            i -= 1
            n1, n2, n3 = get_digits(x)

            if n3 > 0:
                words.append(ONES[n3][0])
                if n3 > 1:
                    words.append(HUNDRED[1])
                else:
                    words.append(HUNDRED[0])

            if n2 > 1:
                words.append(TWENTIES[n2][0])

            if n2 == 1:
                words.append(TENS[n1][0])
            elif n1 > 0:
                if (i == 1 or feminine and i == 0) and n < 1000:
                    words.append(ONES_FEMININE[n1][0])

def _int2word(self, n, feminine=True):
        if n < 0:
            return ' '.join([self.negword, self._int2word(abs(n))])

        if n == 0:
            return ZERO[0]

        words = []
        chunks = list(splitbyx(str(n), 3))
        i = len(chunks)
        for x in chunks:
            i -= 1
            n1, n2, n3 = get_digits(x)

            if n3 > 0:
                words.append(HUNDREDS[n3][0])

            if n2 > 1:
                words.append(TWENTIES[n2][0])

            if n2 == 1:
                words.append(TENS[n1][0])
            # elif n1 > 0 and not (i > 0 and x == 1):
            elif n1 > 0:
                ones = ONES_FEMININE if i == 1 or feminine and i == 0 else ONES
                words.append(ones[n1][0])

            if i > 0 and ((n1 + n2 + n3) > 0):
                words.append(self.pluralize(x, THOUSANDS[i]))

def pluralize(self, n, forms):
        n1, n2, n3 = get_digits(n)
        if n2 == 1 or n1 == 0 or n == 0:
            return forms[2]
        elif n1 == 1:
            return forms[0]
        else:
            return forms[1]

def _int2word(self, number, feminine=False):
        if number < 0:
            return ' '.join([self.negword, self._int2word(abs(number))])

        if number == 0:
            return ZERO[0]

        words = []
        chunks = list(splitbyx(str(number), 3))
        chunk_len = len(chunks)
        for chunk in chunks:
            chunk_len -= 1
            digit_right, digit_mid, digit_left = get_digits(chunk)

            if digit_left > 0:
                words.append(HUNDREDS[digit_left][0])

            if digit_mid > 1:
                words.append(TWENTIES[digit_mid][0])

            if digit_mid == 1:
                words.append(TENS[digit_right][0])
            elif digit_right > 0:
                is_feminine = feminine or SCALE[chunk_len][-1]
                gender_idx = int(is_feminine)
                words.append(
                    ONES[digit_right][gender_idx]
                )

def _int2word(self, n):
        if n == 0:
            return ZERO[0]

        words = []
        chunks = list(splitbyx(str(n), 3))
        i = len(chunks)
        for x in chunks:
            i -= 1
            n1, n2, n3 = get_digits(x)

            if n3 > 0:
                words.append(HUNDREDS[n3][0])

            if n2 > 1:
                words.append(TWENTIES[n2][0])

            if n2 == 1:
                words.append(TENS[n1][0])
            elif n1 > 0 and not (i > 0 and x == 1):
                words.append(ONES[n1][0])

            if i > 0:
                words.append(self.pluralize(x, THOUSANDS[i]))

        return ' '.join(words)