code: def wait_for_completion(self):
      print("...wait")
      for results_ref, time_start_fold, on_fit_end_fn in self.jobs:
          fold_model, time_train_end_fold = ray.get(results_ref)
          print(f"{fold_model} | {time_train_end_fold}")
          on_fit_end_fn(
              fold_model, time_train_end_fold, time_start_fold
          )
  
      ray.shutdown()
  
file_path: autogluon/core/src/autogluon/core/models/ensemble/ray_parallel_fold_fitting_strategy.py
imports: import time
  import ray
  from numpy import ndarray
  from pandas import DataFrame, Series
  from ray.util import placement_group, placement_group_table
  from autogluon.core.models.ensemble.fold_fitting_strategy import SequentialLocalFoldFittingStrategy
label_desc: Use image node_id 3 for calling the RayParallelFitter obj's underlying member method code with example usage: obj.wait_for_completion() without return types