code: def infer_manual_data_interval(self, *, run_after):
      pass
  
imports: from __future__ import annotations
  import inspect
  import pytest
  from flask import Blueprint
  from flask_appbuilder import BaseView
  from airflow.hooks.base import BaseHook
  from airflow.models.baseoperatorlink import BaseOperatorLink
  from airflow.plugins_manager import AirflowPlugin
  from airflow.security import permissions
  from airflow.ti_deps.deps.base_ti_dep import BaseTIDep
  from airflow.timetables.base import Timetable
  from airflow.utils.module_loading import qualname
  from tests.test_utils.api_connexion_utils import assert_401, create_user, delete_user
  from tests.test_utils.config import conf_vars
  from tests.test_utils.mock_plugins import mock_plugin_manager
label_desc: Use image node_id 1 for calling the CustomTimetable obj's underlying member method code with example usage: obj.infer_manual_data_interval() without return types