code: def test_config(self):
      config = dict(
          linkText="Plotly rocks!", showLink=True, editable=True
      )
      html = self._read_html(
          plotly.offline.plot(
              fig,
              config=config,
              auto_open=False,
              filename=html_filename,
          )
      )
      self.assertIn('"linkText": "Plotly rocks!"', html)
      self.assertIn('"showLink": true', html)
      self.assertIn('"editable": true', html)
  
imports: import json
  import os
  from unittest import TestCase
  import pytest
  import plotly
  import plotly.io
  from plotly.io._utils import plotly_cdn_url
label_desc: Use image node_id 16 for calling the PlotlyOfflineTestCase obj's underlying member method code with example usage: obj.test_config() without return types