code: def test_app_state_repr():
      app_state = AppState()
      assert repr(app_state) == "None"
  
      app_state = AppState()
      app_state._store_state({"vars": {"x": 1, "y": 2}})
      assert repr(app_state) == "{'vars': {'x': 1, 'y': 2}}"
  
      app_state = AppState()
      app_state._store_state({"vars": {"x": 1, "y": 2}})
      assert repr(app_state.y) == "2"
  
      app_state = AppState()
      app_state._store_state(
          {
              "vars": {},
              "flows": {"child": {"vars": {"child_var": "child_val"}}},
          }
      )
      assert (
          repr(app_state.child)
          == "{'vars': {'child_var': 'child_val'}}"
      )
  
imports: import os
  from re import escape
  from unittest import mock
  import lightning.app
  import pytest
  import requests
  from lightning.app import LightningApp, LightningFlow, LightningWork
  from lightning.app.structures import Dict, List
  from lightning.app.utilities.app_helpers import AppStatePlugin, BaseStatePlugin
  from lightning.app.utilities.state import AppState
  from lightning_cloud.openapi import Externalv1LightningappInstance, V1LightningappInstanceStatus
label_desc: Use image node_id 5 for calling a global function with example usage: test_app_state_repr() without return types