code: def reserve_trial(
      experiment: Experiment,
      producer: Producer,
      pool_size: int,
      timeout: int | None = None,
  ) -> Trial:
      """Reserve a new trial, or produce and reserve a trial if none are available."""
      log.debug("Trying to reserve a new trial to evaluate.")
  
      if timeout is not None:
          log.warning(
              "Reservation_timeout is deprecated and will be removed in v0.4.0."
              "Use idle_timeout instead."
          )
      trial = None
      produced = 0
  
      # Try to reserve an existing trial
      trial = experiment.reserve_trial()
  
      if trial is None and not (
          experiment.is_broken or experiment.is_done
      ):
          log.debug("#### Produce new trials.")
          produced = producer.produce(pool_size)
          log.debug("#### %s trials produced.", produced)
  
          # Try to reverse once more
          trial = experiment.reserve_trial()
  
      if trial is None:
          if experiment.is_done:
              raise CompletedExperiment()
          elif experiment.is_broken:
              raise BrokenExperiment()
          elif produced == 0:
              raise WaitingForTrials()
          else:
              raise ReservationRaceCondition()
  
      return trial
  
imports: from __future__ import annotations
  import inspect
  import logging
  import numbers
  import typing
  from contextlib import contextmanager
  from typing import Callable
  import orion.core
  from orion.algo.space import Space
  from orion.client.runner import Runner, prepare_trial_working_dir
  from orion.core.io.database import DuplicateKeyError
  from orion.core.utils.exceptions import BrokenExperiment, CompletedExperiment, ReservationRaceCondition, UnsupportedOperation, WaitingForTrials
  from orion.core.utils.format_trials import dict_to_trial
  from orion.core.utils.working_dir import SetupWorkingDir
  from orion.core.worker.experiment import AlgoT
  from orion.core.worker.producer import Producer
  from orion.core.worker.trial import AlreadyReleased, Trial, TrialCM
  from orion.core.worker.trial_pacemaker import TrialPacemaker
  from orion.executor.base import BaseExecutor, executor_factory
  from orion.plotting.base import PlotAccessor
  from orion.storage.base import FailedUpdate
label_desc: Use image node_id 1 for calling a global function with example usage: reserve_trial(experiment, producer, pool_size, timeout) and returns: trial