docs: def css_html(self):
          """
          Render HTML tags for Javascript assets.
  
          Returns:
              string: HTML for CSS assets from every registered config.
          """
          output = io.StringIO()
  
          for item in self.css():
              output.write(
                  self.render_asset_html(item, settings.CODEMIRROR_CSS_ASSET_TAG)
              )
  
          content = output.getvalue()
          output.close()
  
          return content