AbstractStorage::isUnique

public function isUnique($name, $targetDirectoryId, &$opponentId = null);
abstract public function isCorrectName($name, &$msg);

abstract public function getPublicLink(array $objectData);

/**
 * @param $a
 * @param $b
 * @return int (1, -1, 0)
 */
public function compareVersion($a , $b)
{
	$a = str_pad($a, mb_strlen($b), '0', STR_PAD_LEFT);
	$b = str_pad($b, mb_strlen($a), '0', STR_PAD_LEFT);

	return strcmp($a, $b);
}