docstr: Get the next trial to be executed.
  
  :param round_scope: round scope
  :return: the next trial to be executed.
docstr_tok: ["Get","the","next","trial","to","be","executed",".",":","param","round_scope",":","round","scope",":","return",":","the","next","trial","to","be","executed","."]
code: def next_trial(self, round_scope: Round) -> ContextManager[Trial]:
      """
      Get the next trial to be executed.
  
      :param round_scope: round scope
      :return: the next trial to be executed.
      """
      return round_scope.new_rvs_trial(self.continue_loop_on_error)
  
imports: import gc
  from copy import copy
  from typing import ContextManager, Iterator, List, Optional, Tuple
  from neuraxle.base import CX, BaseService, BaseStep, BaseStepT, ExecutionContext, ExecutionMode, ForceHandleMixin, TruncableService, _HasChildrenMixin
  from neuraxle.data_container import ARG_X_INPUTTED, IDT
  from neuraxle.data_container import DataContainer
  from neuraxle.data_container import TrainDACT
  from neuraxle.hyperparams.space import HyperparameterSpace
  from neuraxle.metaopt.callbacks import ARG_Y_EXPECTED, ARG_Y_PREDICTD, BaseCallback, CallbackList, MetricCallback, ScoringCallback
  from neuraxle.metaopt.context import AutoMLContext
  from neuraxle.metaopt.data.aggregates import Client, Project, Root, Round, Trial, TrialSplit
  from neuraxle.metaopt.data.reporting import RoundReport
  from neuraxle.metaopt.data.vanilla import DEFAULT_CLIENT, DEFAULT_PROJECT, RoundDataclass, ScopedLocation
  from neuraxle.metaopt.optimizer import BaseHyperparameterOptimizer, GridExplorationSampler, RandomSearchSampler
  from neuraxle.metaopt.repositories.repo import HyperparamsRepository
  from neuraxle.metaopt.validation import BaseValidationSplitter, ValidationSplitter
label_desc: Use image node_id 5 for calling the BaseControllerLoop obj's underlying member method code with example usage: obj.next_trial(round_scope) and returns: round_scope