code: def benchmark(workers, size):
      """Get start timestamps of the trials
  
      Parameters
      ----------
      workers: int
          see: `stress_test`.
      size: int
          See `get_experiment`.
  
      Returns
      -------
      dict
          Dictionary containing all results of all stress tests.
          Each key is (backend, space_type). See `get_experiment` for the supported types
          of `backend`s and `space_type`s. Each values result[(backend, space_type)] is
          in the form of a (x, y) tuple, where x a the list start timestamps and y is the indexes of
          the trials. See `get_timestamps` for more details.
  
      """
      results = {}
      for backend in ["mongodb", "pickleddb"]:
          for space_type in ["discrete", "real", "real-seeded"]:
              trials = stress_test(backend, space_type, workers, size)
              results[(backend, space_type)] = get_timestamps(
                  trials, size, space_type
              )
  
      return results
  
file_path: orion/tests/stress/client/stress_experiment.py
imports: import os
  import random
  import time
  import traceback
  from multiprocessing import Pool
  import matplotlib.pyplot
  from pymongo import MongoClient
  from orion.client import create_experiment
  from orion.core.io.database import DatabaseTimeout
  from orion.core.utils.exceptions import ReservationTimeout
label_desc: Use image node_id 6 for calling a global function with example usage: benchmark(workers, size) and returns: results