code: def render(self, template=None, additional=None):
          
          template_path = template or self.get_template_path()
  
          template_vars = {'model': self}
          if additional:
              template_vars.update(additional)
  
          rendered = render_to_string(template_path, template_vars)
          return mark_safe(rendered)
docs: Render single model to its html representation.
  
          You may set template path in render function argument,
              or model's variable named 'template_path',
              or get default name: $app_label$/models/$model_name$.html
  
          Settings:
          * MODEL_RENDER_DEFAULT_EXTENSION
              set default template extension. Usable if you use jinja or others.
  
          :param template: custom template_path
          :return: rendered model html string