code: def test_count(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")
  
      session.add(
          TrialModel(
              study_id=study_1.study_id, state=TrialState.COMPLETE
          )
      )
      session.add(
          TrialModel(
              study_id=study_1.study_id, state=TrialState.RUNNING
          )
      )
      session.add(
          TrialModel(
              study_id=study_2.study_id, state=TrialState.RUNNING
          )
      )
      session.commit()
  
      assert 3 == TrialModel.count(session)
      assert 2 == TrialModel.count(session, study=study_1)
      assert 1 == TrialModel.count(session, state=TrialState.COMPLETE)
  
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 2 for calling the TestTrialModel obj's underlying member method code with example usage: obj.test_count(session) without return types