code: def clean_db():
      clear_db_runs()
      clear_db_dags()
      clear_db_xcom()
  
imports: from __future__ import annotations
  from contextlib import nullcontext
  import pytest
  from airflow.decorators import task
  from airflow.exceptions import ParamValidationError, RemovedInAirflow3Warning
  from airflow.models.param import Param, ParamsDict
  from airflow.serialization.serialized_objects import BaseSerialization
  from airflow.utils import timezone
  from airflow.utils.types import DagRunType
  from tests.test_utils.db import clear_db_dags, clear_db_runs, clear_db_xcom
label_desc: Use image node_id 1 for calling the TestDagParamRuntime obj's underlying member method code with example usage: obj.clean_db() without return types