def _convert_range_to_list(self, tgt):
        '''
        convert a seco.range range into a list target
        '''
        range_ = seco.range.Range(self.opts['range_server'])
        try:
            return range_.expand(tgt)
        except seco.range.RangeException as err:
            print('Range server exception: {0}'.format(err))
            return []