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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 SetTimezone(self, timezone):
 """Sets the timezone. Args: timezone (str):
 timezone. Raises: ValueError: if the timezone is not supported. """

    if not timezone:
      return

    try:
      self._timezone = pytz.timezone(timezone)
    except pytz.UnknownTimeZoneError:
      raise ValueError('Unsupported timezone: {0:s}'.format(timezone))