class_docstr: OnlineManager can manage online models with `Online Strategy <#Online Strategy>`_.
  It also provides a history recording of which models are online at what time.
docstr: Add some new strategies to OnlineManager.
  
  Args:
      strategy (Union[OnlineStrategy, List[OnlineStrategy]]): a list of OnlineStrategy
docstr_tok: ["Add","some","new","strategies","to","OnlineManager",".","Args",":","strategy","(","Union","[","OnlineStrategy",",","List","[","OnlineStrategy","]","]",")",":","a","list","of","OnlineStrategy"]
code: def add_strategy(
      self, strategies: Union[OnlineStrategy, List[OnlineStrategy]]
  ):
      """
      Add some new strategies to OnlineManager.
  
      Args:
          strategy (Union[OnlineStrategy, List[OnlineStrategy]]): a list of OnlineStrategy
      """
      if not isinstance(strategies, list):
          strategies = [strategies]
      self.first_train(strategies)
      self.strategies.extend(strategies)
  
imports: import logging
  from typing import Callable, List, Union
  import pandas
  from qlib import get_module_logger
  from qlib.data.data import D
  from qlib.log import set_global_logger_level
  from qlib.model.ens.ensemble import AverageEnsemble
  from qlib.model.trainer import Trainer, TrainerR
  from qlib.utils.serial import Serializable
  from qlib.workflow.online.strategy import OnlineStrategy
  from qlib.workflow.task.collect import MergeCollector
label_desc: Use image node_id 6 for calling the OnlineManager obj's underlying member method code with example usage: obj.add_strategy(strategies) without return types