code: def _estimate_min_resource(
      trials: List["optuna.trial.FrozenTrial"],
  ) -> Optional[int]:
      n_steps = [
          t.last_step
          for t in trials
          if t.state == TrialState.COMPLETE and t.last_step is not None
      ]
  
      if not n_steps:
          return None
  
      # Get the maximum number of steps and divide it by 100.
      last_step = max(n_steps)
      return max(last_step // 100, 1)
  
file_path: optuna/optuna/pruners/_successive_halving.py
imports: import math
  from typing import List
  from typing import Optional
  from typing import Union
  import optuna
  from optuna.pruners._base import BasePruner
  from optuna.study._study_direction import StudyDirection
  from optuna.trial._state import TrialState
label_desc: Use image node_id 1 for calling a global function with example usage: _estimate_min_resource(trials) and returns: max, None