public function get_object_acl($bucket, $object, $opt = array())
{
$this->assertParameterArray($opt);
$opt[self::BUCKET] = $bucket;
$opt[self::METHOD] = 'GET';
$opt[self::OBJECT] = $object;
$opt[self::QUERY_STRING] = array(self::ACL => 1);
$response = $this->authenticate($opt);
$this->log($response->isOK() ? "Get object acl success!" : "Get object acl failed! Response: [" . $response->body . "]", $opt);
return $response;
}