class_docstr: Status and results of a :class:`~optuna.multi_objective.trial.MultiObjectiveTrial`.
  
  Attributes:
      number:
          Unique and consecutive number of
          :class:`~optuna.multi_objective.trial.MultiObjectiveTrial` for each
          :class:`~optuna.multi_objective.study.MultiObjectiveStudy`.
          Note that this field uses zero-based numbering.
      state:
          :class:`~optuna.trial.TrialState` of the
          :class:`~optuna.multi_objective.trial.MultiObjectiveTrial`.
      values:
          Objective values of the :class:`~optuna.multi_objective.trial.MultiObjectiveTrial`.
      datetime_start:
          Datetime where the :class:`~optuna.multi_objective.trial.MultiObjectiveTrial` started.
      datetime_complete:
          Datetime where the :class:`~optuna.multi_objective.trial.MultiObjectiveTrial` finished.
      params:
          Dictionary that contains suggested parameters.
      distributions:
          Dictionary that contains the distributions of :attr:`params`.
      user_attrs:
          Dictionary that contains the attributes of the
          :class:`~optuna.multi_objective.trial.MultiObjectiveTrial` set with
          :func:`optuna.multi_objective.trial.MultiObjectiveTrial.set_user_attr`.
      intermediate_values:
          Intermediate objective values set with
          :func:`optuna.multi_objective.trial.MultiObjectiveTrial.report`.
code: def user_attrs(self) -> Dict[str, Any]:
      return self._trial.user_attrs
  
imports: from datetime import datetime
  from typing import Any
  from typing import Dict
  from typing import List
  from typing import Optional
  from typing import overload
  from typing import Sequence
  from typing import Union
  from optuna import multi_objective
  from optuna._convert_positional_args import convert_positional_args
  from optuna._deprecated import deprecated_class
  from optuna.distributions import BaseDistribution
  from optuna.study._study_direction import StudyDirection
  from optuna.trial import FrozenTrial
  from optuna.trial import Trial
  from optuna.trial import TrialState
  from optuna.trial._base import _SUGGEST_INT_POSITIONAL_ARGS
label_desc: Use image node_id 8 for calling the FrozenMultiObjectiveTrial obj's underlying member method code with example usage: obj.user_attrs() and returns: self