code: def test_app(self):
      response = self.client.get("/")
      html = response.get_data().decode("utf-8")
  
      assert "AllenNLP Configuration Wizard" in html
  
imports: from __future__ import with_statement
  from __future__ import division
  from __future__ import absolute_import
  from __future__ import print_function
  import json
  import os
  import pathlib
  import sys
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.service import config_explorer
  from allennlp.service.config_explorer import make_app, _HTML
  from io import open
label_desc: Use image node_id 3 for calling the TestConfigExplorer obj's underlying member method code with example usage: obj.test_app() without return types