How to use the gtts.utils._len function in gTTS

def _tokenize(self, text):
        # Pre-clean
        text = text.strip()

        # Apply pre-processors
        for pp in self.pre_processor_funcs:
            log.debug("pre-processing: %s", pp)
            text = pp(text)

        if _len(text) <= self.GOOGLE_TTS_MAX_CHARS:
            return _clean_tokens([text])

        # Tokenize
        log.debug("tokenizing: %s", self.tokenizer_func)
        tokens = self.tokenizer_func(text)

        # Clean
        tokens = _clean_tokens(tokens)

        # Minimize
        min_tokens = []
        for t in tokens:
            min_tokens += _minimize(t, ' ', self.GOOGLE_TTS_MAX_CHARS)
        return min_tokens

# Calculate token
                part_tk = self.token.calculate_token(part)
            except requests.exceptions.RequestException as e:  # pragma: no cover
                log.debug(str(e), exc_info=True)
                raise gTTSError(
                    "Connection error during token calculation: %s" %
                    str(e))

            payload = {'ie': 'UTF-8',
                       'q': part,
                       'tl': self.lang,
                       'ttsspeed': self.speed,
                       'total': len(text_parts),
                       'idx': idx,
                       'client': 'tw-ob',
                       'textlen': _len(part),
                       'tk': part_tk}

            log.debug("payload-%i: %s", idx, payload)

            try:
                # Request
                r = requests.get(self.GOOGLE_TTS_URL,
                                 params=payload,
                                 headers=self.GOOGLE_TTS_HEADERS,
                                 proxies=urllib.request.getproxies(),
                                 verify=False)

                log.debug("headers-%i: %s", idx, r.request.headers)
                log.debug("url-%i: %s", idx, r.request.url)
                log.debug("status-%i: %s", idx, r.status_code)

# Calculate token
                part_tk = self.token.calculate_token(part)
            except requests.exceptions.RequestException as e:  # pragma: no cover
                log.debug(str(e), exc_info=True)
                raise gTTSError(
                    "Connection error during token calculation: %s" %
                    str(e))

            payload = {'ie': 'UTF-8',
                       'q': part,
                       'tl': self.lang,
                       'ttsspeed': self.speed,
                       'total': len(text_parts),
                       'idx': idx,
                       'client': 'tw-ob',
                       'textlen': _len(part),
                       'tk': part_tk}

            log.debug("payload-%i: %s", idx, payload)

            try:
                # Request
                r = requests.get(self.GOOGLE_TTS_URL,
                                 params=payload,
                                 headers=self.GOOGLE_TTS_HEADERS,
                                 proxies=urllib.request.getproxies(),
                                 verify=False)

                log.debug("headers-%i: %s", idx, r.request.headers)
                log.debug("url-%i: %s", idx, r.request.url)
                log.debug("status-%i: %s", idx, r.status_code)

def _tokenize(self, text):
        # Pre-clean
        text = text.strip()

        # Apply pre-processors
        for pp in self.pre_processor_funcs:
            log.debug("pre-processing: %s", pp)
            text = pp(text)

        if _len(text) <= self.GOOGLE_TTS_MAX_CHARS:
            return _clean_tokens([text])

        # Tokenize
        log.debug("tokenizing: %s", self.tokenizer_func)
        tokens = self.tokenizer_func(text)

        # Clean
        tokens = _clean_tokens(tokens)

        # Minimize
        min_tokens = []
        for t in tokens:
            min_tokens += _minimize(t, ' ', self.GOOGLE_TTS_MAX_CHARS)
        return min_tokens

def _tokenize(self, text):
        # Pre-clean
        text = text.strip()

        # Apply pre-processors
        for pp in self.pre_processor_funcs:
            log.debug("pre-processing: %s", pp)
            text = pp(text)

        if _len(text) <= self.GOOGLE_TTS_MAX_CHARS:
            return _clean_tokens([text])

        # Tokenize
        log.debug("tokenizing: %s", self.tokenizer_func)
        tokens = self.tokenizer_func(text)

        # Clean
        tokens = _clean_tokens(tokens)

        # Minimize
        min_tokens = []
        for t in tokens:
            min_tokens += _minimize(t, ' ', self.GOOGLE_TTS_MAX_CHARS)
        return min_tokens

# Calculate token
                part_tk = self.token.calculate_token(part)
            except requests.exceptions.RequestException as e:  # pragma: no cover
                log.debug(str(e), exc_info=True)
                raise gTTSError(
                    "Connection error during token calculation: %s" %
                    str(e))

            payload = {'ie': 'UTF-8',
                       'q': part,
                       'tl': self.lang,
                       'ttsspeed': self.speed,
                       'total': len(text_parts),
                       'idx': idx,
                       'client': 'tw-ob',
                       'textlen': _len(part),
                       'tk': part_tk}

            log.debug("payload-%i: %s", idx, payload)

            try:
                # Request
                r = requests.get(self.GOOGLE_TTS_URL,
                                 params=payload,
                                 headers=self.GOOGLE_TTS_HEADERS,
                                 proxies=urllib.request.getproxies(),
                                 verify=False)

                log.debug("headers-%i: %s", idx, r.request.headers)
                log.debug("url-%i: %s", idx, r.request.url)
                log.debug("status-%i: %s", idx, r.status_code)