Posting to Timeline using PHP SDK 4.0.x

fb-post-4.0.x.php

<?php

// make api call
$response = (new FacebookRequest(
    $session, 'POST', '/me/feed', array(
      'message' => 'testing'
    )
  ))->execute()->getGraphObject()->asArray();

// output response - should include post_id
print_r( $response );