docs: def render(file):
      """Generate the result HTML."""
      fp = file.open()
      content = fp.read()
      fp.close()
  
      notebook = nbformat.reads(content.decode('utf-8'), as_version=4)
  
      html_exporter = HTMLExporter()
      html_exporter.template_file = 'basic'
      (body, resources) = html_exporter.from_notebook_node(notebook)
      return body, resources