public function getContents($row)
    {
        if (is_callable($this->options['callable'])) {
            if (is_array($this->options['callable'])) {
                return call_user_func($this->options['callable'], [$row]);
            }

            return $this->options['callable']($row);
        }

        $propertyAccessor = PropertyAccess::createPropertyAccessor();

        try {
            return $propertyAccessor->getValue($row, $this->options['accessor_path']);
        } catch (UnexpectedTypeException $e) {
            return '';
        } catch (NoSuchPropertyException $e) {
            return $e->getMessage();
        }
    }