public static function GetInstance($exp_time = 3600, $path = 'cache/')
{
if ($path[strlen($path) - 1] != '/') {
$path .= '/';
}
if (!isset(self::$instance)) {
//doesn't exists the isntance
self::$instance = new self($exp_time, $path);
//goes to the constructor
}
return self::$instance;
}
