How to use the dateparser.utils.apply_timezone function in dateparser

def test_apply_timezone_function(self, date, timezone, expected):
        result = apply_timezone(date, timezone)
        result = result.replace(tzinfo=None)
        self.assertEqual(expected, result)

if not self.now.tzinfo:
                self.now = self.get_local_tz().localize(self.now)

        elif ptz:
            _now = datetime.now(ptz)

            if 'local' in _settings_tz:
                self.now = _now
            else:
                self.now = apply_timezone(_now, settings.TIMEZONE)

        else:
            if 'local' not in _settings_tz:
                utc_dt = datetime.utcnow()
                self.now = apply_timezone(utc_dt, settings.TIMEZONE)
            else:
                self.now = datetime.now(self.get_local_tz())

        date, period = self._parse_date(date_string)

        if date:
            date = apply_time(date, _time)
            if settings.TO_TIMEZONE:
                date = apply_timezone(date, settings.TO_TIMEZONE)

            if (
                not settings.RETURN_AS_TIMEZONE_AWARE or
                (settings.RETURN_AS_TIMEZONE_AWARE and
                 'default' == settings.RETURN_AS_TIMEZONE_AWARE and not ptz)
            ):
                date = date.replace(tzinfo=None)

if ptz:
                if self.now.tzinfo:
                    self.now = self.now.astimezone(ptz)
                else:
                    self.now = ptz.localize(self.now)

            if not self.now.tzinfo:
                self.now = self.get_local_tz().localize(self.now)

        elif ptz:
            _now = datetime.now(ptz)

            if 'local' in _settings_tz:
                self.now = _now
            else:
                self.now = apply_timezone(_now, settings.TIMEZONE)

        else:
            if 'local' not in _settings_tz:
                utc_dt = datetime.utcnow()
                self.now = apply_timezone(utc_dt, settings.TIMEZONE)
            else:
                self.now = datetime.now(self.get_local_tz())

        date, period = self._parse_date(date_string)

        if date:
            date = apply_time(date, _time)
            if settings.TO_TIMEZONE:
                date = apply_timezone(date, settings.TO_TIMEZONE)

            if (

else:
                self.now = apply_timezone(_now, settings.TIMEZONE)

        else:
            if 'local' not in _settings_tz:
                utc_dt = datetime.utcnow()
                self.now = apply_timezone(utc_dt, settings.TIMEZONE)
            else:
                self.now = datetime.now(self.get_local_tz())

        date, period = self._parse_date(date_string)

        if date:
            date = apply_time(date, _time)
            if settings.TO_TIMEZONE:
                date = apply_timezone(date, settings.TO_TIMEZONE)

            if (
                not settings.RETURN_AS_TIMEZONE_AWARE or
                (settings.RETURN_AS_TIMEZONE_AWARE and
                 'default' == settings.RETURN_AS_TIMEZONE_AWARE and not ptz)
            ):
                date = date.replace(tzinfo=None)

        self.now = None
        return date, period

date_string = six.text_type(date_string)

        if not date_string.strip():
            raise ValueError("Empty string")

        date_string = strip_braces(date_string)
        date_string, ptz = pop_tz_offset_from_string(date_string)

        date_obj, period = parse(date_string, settings=settings)

        _settings_tz = settings.TIMEZONE.lower()

        if ptz:
            date_obj = ptz.localize(date_obj)
            if 'local' not in _settings_tz:
                date_obj = apply_timezone(date_obj, settings.TIMEZONE)
        else:
            if 'local' in _settings_tz:
                stz = get_localzone()
                date_obj = stz.localize(date_obj)
            else:
                date_obj = localize_timezone(date_obj, settings.TIMEZONE)

        if settings.TO_TIMEZONE:
            date_obj = apply_timezone(date_obj, settings.TO_TIMEZONE)

        if (
            not settings.RETURN_AS_TIMEZONE_AWARE or
            (settings.RETURN_AS_TIMEZONE_AWARE and
             'default' == settings.RETURN_AS_TIMEZONE_AWARE and not ptz)
        ):
            date_obj = date_obj.replace(tzinfo=None)

_settings_tz = settings.TIMEZONE.lower()

        if ptz:
            date_obj = ptz.localize(date_obj)
            if 'local' not in _settings_tz:
                date_obj = apply_timezone(date_obj, settings.TIMEZONE)
        else:
            if 'local' in _settings_tz:
                stz = get_localzone()
                date_obj = stz.localize(date_obj)
            else:
                date_obj = localize_timezone(date_obj, settings.TIMEZONE)

        if settings.TO_TIMEZONE:
            date_obj = apply_timezone(date_obj, settings.TO_TIMEZONE)

        if (
            not settings.RETURN_AS_TIMEZONE_AWARE or
            (settings.RETURN_AS_TIMEZONE_AWARE and
             'default' == settings.RETURN_AS_TIMEZONE_AWARE and not ptz)
        ):
            date_obj = date_obj.replace(tzinfo=None)

        return date_obj, period