class_docstr: A result tracker which delegates to multiple different result trackers.
code: def start_run(
      self, run_name: Optional[str] = None
  ) -> None:  # noqa: D102
      for tracker in self.trackers:
          tracker.start_run(run_name=run_name)
  
imports: import logging
  import re
  from collections import defaultdict
  from typing import Any, Iterable, List, Mapping, MutableMapping, Optional, Pattern, Union
  from tqdm.auto import tqdm
  from ..utils import flatten_dictionary
label_desc: Use image node_id 2 for calling the MultiResultTracker obj's underlying member method code with example usage: obj.start_run(run_name) without return types