code: def test_div_output(self):
      html = plotly.offline.plot(
          fig, output_type="div", auto_open=False
      )
  
      self.assertNotIn("<html>", html)
      self.assertNotIn("</html>", html)
      self.assertTrue(
          html.startswith("<div>") and html.endswith("</div>")
      )
  
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 15 for calling the PlotlyOfflineTestCase obj's underlying member method code with example usage: obj.test_div_output() without return types