public function getFieldDescription($field)
    {
        $item = $this->fields->find('Name', $field);

        if (!$item) {
            throw new Exception(
                sprintf(
                    'Tried to get field description for %s, but it has not been added to %s',
                    $field,
                    $this->getDataObjectClass()
                )
            );
        }

        return $item->Description;
    }