code: def test_count_past_trials(session: Session) -> None:
      study_1 = StudyModel(study_id=1, study_name="test-study-1")
      study_2 = StudyModel(study_id=2, study_name="test-study-2")
  
      trial_1_1 = TrialModel(
          study_id=study_1.study_id, state=TrialState.COMPLETE
      )
      session.add(trial_1_1)
      session.commit()
      assert 0 == trial_1_1.count_past_trials(session)
  
      trial_1_2 = TrialModel(
          study_id=study_1.study_id, state=TrialState.RUNNING
      )
      session.add(trial_1_2)
      session.commit()
      assert 1 == trial_1_2.count_past_trials(session)
  
      trial_2_1 = TrialModel(
          study_id=study_2.study_id, state=TrialState.RUNNING
      )
      session.add(trial_2_1)
      session.commit()
      assert 0 == trial_2_1.count_past_trials(session)
  
imports: from datetime import datetime
  import pytest
  from sqlalchemy import create_engine
  from sqlalchemy.exc import IntegrityError
  from sqlalchemy.orm import Session
  from optuna.storages._rdb.models import BaseModel
  from optuna.storages._rdb.models import StudyDirectionModel
  from optuna.storages._rdb.models import StudyModel
  from optuna.storages._rdb.models import StudySystemAttributeModel
  from optuna.storages._rdb.models import TrialHeartbeatModel
  from optuna.storages._rdb.models import TrialIntermediateValueModel
  from optuna.storages._rdb.models import TrialModel
  from optuna.storages._rdb.models import TrialSystemAttributeModel
  from optuna.storages._rdb.models import TrialUserAttributeModel
  from optuna.storages._rdb.models import TrialValueModel
  from optuna.storages._rdb.models import VersionInfoModel
  from optuna.study._study_direction import StudyDirection
  from optuna.trial import TrialState
label_desc: Use image node_id 3 for calling the TestTrialModel obj's underlying member method code with example usage: obj.test_count_past_trials(session) without return types