class_docstr: Class for synthetic or dummy runner.
  
  Currently acts as a shell runner, only creating a name.
code: def poll_trial_status(
      self, trials: Iterable[BaseTrial]
  ) -> Dict[TrialStatus, Set[int]]:
      return {TrialStatus.COMPLETED: {t.index for t in trials}}
  
file_path: Ax/ax/runners/synthetic.py
imports: from typing import Any, Dict, Iterable, List, Optional, Set
  from ax.core.base_trial import BaseTrial, TrialStatus
  from ax.core.runner import Runner
label_desc: Use image node_id 3 for calling the SyntheticRunner obj's underlying member method code with example usage: obj.poll_trial_status(trials) and returns: dict