<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _get_timezone(self, tz):
 """ Find and return the time zone if possible """

        # special Local timezone
        if tz == "Local":
            try:
                return tzlocal.get_localzone()
            except pytz.UnknownTimeZoneError:
                return "?"

        # we can use a country code to get tz
        # FIXME this is broken for multi-timezone countries eg US
        # for now we just grab the first one
        if len(tz) == 2:
            try:
                zones = pytz.country_timezones(tz)
            except KeyError:
                return "?"
            tz = zones[0]

        # get the timezone
        try:
            zone = pytz.timezone(tz)
        except pytz.UnknownTimeZoneError:
            return "?"
        return zone