code: def set_trial_system_attr(
      self, _: int, key: str, value: dict
  ) -> None:
      self.value[key] = value
  
file_path: optuna/tests/multi_objective_tests/samplers_tests/test_motpe.py
imports: from typing import Dict
  from typing import Tuple
  from unittest.mock import Mock
  from unittest.mock import patch
  import pytest
  import optuna
  from optuna import multi_objective
  from optuna.multi_objective.samplers import MOTPEMultiObjectiveSampler
  from optuna.samplers import MOTPESampler
label_desc: Use image node_id 2 for calling the MockSystemAttr obj's underlying member method code with example usage: obj.set_trial_system_attr(_, key, value) without return types