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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 set_zone(time_zone):
    '''
    Set the local time zone. Use ``timezone.list_zones`` to list valid time_zone
    arguments

    :param str time_zone: The time zone to apply

    :return: True if successful, False if not
    :rtype: bool

    :raises: SaltInvocationError on Invalid Timezone
    :raises: CommandExecutionError on failure

    CLI Example:

    .. code-block:: bash

        salt '*' timezone.set_zone America/Denver
    '''
    if time_zone not in list_zones():
        raise SaltInvocationError('Invalid Timezone: {0}'.format(time_zone))

    salt.utils.mac_utils.execute_return_success(
        'systemsetup -settimezone {0}'.format(time_zone))

    return time_zone in get_zone()