code: def test_create_html_report(self):
      specs = [
          {"id": "my_chart_name", "chart": sample_chart()},
          {"id": "some_html", "html": "<h2>SOME HTML</h2>"},
      ]
  
      html_output = io.StringIO()
      dashboard_utils.create_html_report(
          specs=specs,
          html_output=html_output,
          title="my fancy title",
          subtitle="my fancy subtitle",
          include_outline=True,
      )
  
      html = html_output.getvalue()
      self.assertIn(
          "my_chart_name",
          html,
          msg="Chart ID is missing from the HTML.",
      )
      self.assertIn(
          "point", html, msg="Vega specs may be missing from the HTML."
      )
      self.assertIn(
          "my fancy title",
          html,
          msg="The title is missing from the HTML.",
      )
      self.assertIn(
          "my fancy subtitle",
          html,
          msg="The subtitle is missing from the HTML.",
      )
      self.assertIn("_blank", html, msg="Embed options missing.")
      self.assertIn(
          "<h2>SOME HTML</h2>", html, msg="Custom html is missing."
      )
  
file_path: deepvariant/deepvariant/dashboard_utils_test.py
imports: import io
  from absl.testing import absltest
  from absl.testing import parameterized
  import altair
  import pandas
  from deepvariant import dashboard_utils
label_desc: Use image node_id 1 for calling the DashboardUtilsTest obj's underlying member method code with example usage: obj.test_create_html_report() without return types