public function is_object_exist($bucket, $object, $options = null)
{
//options
$this->validate_options($options);
if (!$options) {
$options = array();
}
//bucket
$this->is_empty($bucket, OSS_BUCKET_IS_NOT_ALLOWED_EMPTY);
//object
$this->is_empty($object, OSS_OBJECT_IS_NOT_ALLOWED_EMPTY);
$options[self::OSS_BUCKET] = $bucket;
$options[self::OSS_METHOD] = 'GET';
$options[self::OSS_OBJECT] = $object;
$response = $this->get_object_meta($bucket, $object, $options);
return $response;
}