如何获得Facebook链接的评论

Question

I have some trouble with de Facebook API (PHP SDK). I'm working in a CMS, and when a new post/page is created, this can be shared to Facebook. Like this:

$response = ( new FacebookRequest(
    $session, 'POST', '/me/feed', array(
        'link'    => $url,
        'message' => $message
    )
) )->execute()->getGraphObject();

After I posted the link, I'll get the ID and save it to the database:

$response->getProperty( 'id' );

The ID is something like this: 1387893784860228_1395000904149516

Now I want to pull the comments, so I try this:

$response = ( new FacebookRequest(
    $session, 'GET', '/1387893784860228_1395000904149516/comments'
) )->execute()->getGraphObject();

The result is empty, but I posted multiple comments, does somebody know what I'm doing wrong?

Thx in advance!