code: def render_string(self, template_name: str, **kwargs: Any) -> bytes:
          
          # If no template_path is specified, use the path of the calling file
          template_path = self.get_template_path()
          if not template_path:
              frame = sys._getframe(0)
              web_file = frame.f_code.co_filename
              while frame.f_code.co_filename == web_file:
                  frame = frame.f_back
              assert frame.f_code.co_filename is not None
              template_path = os.path.dirname(frame.f_code.co_filename)
          with RequestHandler._template_loader_lock:
              if template_path not in RequestHandler._template_loaders:
                  loader = self.create_template_loader(template_path)
                  RequestHandler._template_loaders[template_path] = loader
              else:
                  loader = RequestHandler._template_loaders[template_path]
          t = loader.load(template_name)
          namespace = self.get_template_namespace()
          namespace.update(kwargs)
          return t.generate(**namespace)
docs: Generate the given template with the given arguments.
  
          We return the generated byte string (in utf8). To generate and
          write a template as a response, use render() above.