/**
* @param UserDocument $friend
* @param integer $n
*
* @return array
*/
public function getFriendsFriends($friend, $n)
{
if ($n > 0) {
$friendsFriends = $friend->getFriends();
foreach ($friendsFriends as $friendsFriend) {
$this->friendsFriends[] = $friendsFriend->getEmail();
$this->getFriendsFriends($friendsFriend, $n - 1);
}
}
return array_unique($this->friendsFriends);
}
