code: def visit_literal_block(self, node):
          
          language = node.attributes.get("language", "")
          test_type = node.attributes.get("testnodetype", "")
          if test_type != "doctest":
              if language.lower() in ("", "python"):
                  msg = _LITERAL_ERR_TEMPLATE.format(
                      node.rawsource, language, test_type
                  )
                  raise errors.ExtensionError(msg)
  
          # The base classes are not new-style, so we can't use super().
          return html.HTMLTranslator.visit_literal_block(self, node)
docs: Visit a ``literal_block`` node.
  
          This verifies the state of each literal / code block.