docs: def xpath_book(request, uuid, version, return_json=True):
      """
      Given a request, book UUID and version:
  
      returns a JSON object or HTML list of results, each result containing:
      module_name,
      module_uuid,
      xpath_results, an array of strings, each an individual xpath result.
      """
  
      xpath_string = request.params.get('q')
      results = execute_xpath(xpath_string, 'xpath', uuid, version)
      if return_json:
          return results
      else:
          return xpath_book_html(request, results)