protected function makeComparable($value, $parameter)
    {

        if (!$value instanceof DateTimeInterface && !$parameter instanceof DateTimeInterface) {
            return [$this->getSize($value), $parameter];
        }

        // One is datetime
        try {
            $value = $this->toTimestamp($value);
            $parameter = $this->toTimestamp($parameter);
            return [$value, $parameter];
        } catch (InvalidArgumentException $e) {
            return [];
        }

    }