human
Solve the following python programming problem given the following code:
@ _auth_return_future 
def facebook_request(self, path, callback, access_token = None, post_args = None, **args) : 
    'Fetches the given relative API path, e.g., "/btaylor/picture"

        If the request is a POST, ``post_args`` should be provided. Query
        string arguments should be given as keyword arguments.

        An introduction to the Facebook Graph API can be found at
        http://developers.facebook.com/docs/api

        Many methods require an OAuth access token which you can
        obtain through `~OAuth2Mixin.authorize_redirect` and
        `get_authenticated_user`. The user returned through that
        process includes an ``access_token`` attribute that can be
        used to make authenticated requests via this method.

        Example usage::

            class MainHandler(tornado.web.RequestHandler,
                              tornado.auth.FacebookGraphMixin):
                @tornado.web.authenticated
                @tornado.web.asynchronous
                @tornado.gen.coroutine
                def get(self):
                    new_entry = yield self.facebook_request(
                        "/me/feed",
                        post_args={"message": "I am posting from my Tornado application!"},
                        access_token=self.current_user["access_token"])

                    if not new_entry:
                        # Call failed.
perhaps missing permission?
                        yield self.authorize_redirect()
                        return
                    self.finish("Posted a message!")

        The given path is relative to ``self._FACEBOOK_BASE_URL``,
        by default "https://graph.facebook.com".

        .. versionchanged:: 3.1
           Added the ability to override ``self._FACEBOOK_BASE_URL``.
        ' 
    url = (self._FACEBOOK_BASE_URL + path) 
    all_args = { 
        
} 
    if access_token : 
        all_args ['access_token'] = access_token 
        all_args.update (args) 
if all_args : 
        url += ('?' + urllib_parse.urlencode...

    
    

    Fix the buggy line: http.fetch (url, method = 'POST', body = urllib_parse.urlencode (post_args), callback = path)
assistant
#Here is Python program to fix the buggy line: http.

http.fetch (url, method = 'POST', body = urllib_parse.urlencode (post_args), callback = callback)