public function checkDue($segment, $pos, $times)
    {
        $isDue   = true;
        $offsets = \explode(',', \trim($segment));

        foreach ($offsets as $offset) {
            if (null === $isDue = $this->isOffsetDue($offset, $pos, $times)) {
                throw new \UnexpectedValueException(
                    sprintf('Invalid offset value at segment #%d: %s', $pos, $offset)
                );
            }

            if ($isDue) {
                return true;
            }
        }

        return false;
    }