public function getMultiple($keys, $default = null)
    {
        $result = [];
        foreach ($keys as $key) {
            $result[$key] = $default;
        }
        return $result;
    }
public function getMultiple($keys, $default = null)
    {
        $result = [];
        foreach ($keys as $key) {
            $result[$key] = $default;
        }
        return $result;
    }
{@inheritdoc}