public static function set($key, $value = '')
{
empty(self::$prefix) && (self::$prefix = Config::get('session_prefix'));
if (!is_array($key)) {
$_SESSION[self::$prefix . $key] = $value;
} else {
foreach ($key as $k => $v) {
$_SESSION[self::$prefix . $k] = $v;
}
}
return true;
}