code: def from_config(config, **options):
          
          required_args = ('storage-backends',)
          optional_args = {'events_per_batch': 25000}
          rconfig.check_config_options("SyncedRotationEventStores",
                                       required_args,
                                       tuple(optional_args.keys()), options)
  
          if "events_per_batch" in options:
              events_per_batch = int(options["events_per_batch"])
          else:
              events_per_batch = optional_args["events_per_batch"]
  
          estore = SyncedRotationEventStores(events_per_batch)
  
          for section in options['storage-backends'].split(' '):
              try:
                  substore = rconfig.construct_eventstore(config, section)
                  estore.add_rotated_store(substore)
              except Exception as e:
                  _logger.exception('Could not instantiate substore from'
                                    ' section %s', section)
                  estore.close()
                  raise
  
          return estore
docs: Instantiate an `SyncedRotationEventStores` from config.
  
          Parameters:
          config    -- the configuration file options read from file(s).
          **options -- various options given to the specific event store. Shall
                       not be used with this event store. Warning will be logged
                       for every extra non-recognized option. The only required
                       key to this function is 'path'.
  
          returns   -- a newly instantiated `SyncedRotationEventStores`.