code: def update(self, id, **kwargs):
          
  
          return super(PostController, self).update(id, **self._with_markdown(kwargs))
docs: Updates an existing post.
          When the `markdown` property is present, it will be
          automatically converted to `mobiledoc` on v1.+ of the server.
  
          :param id: The ID of the existing post
          :param kwargs: The properties of the post to change
          :return: The updated `Post` object