public function addField(Field $field)
    {
        $field
            ->setSection($this->currentSection)
            ->setOptionName($this->registry['option_name'])
        ;

        if (isset($this->registry['field_values'][$field->getId()])) {
            $field->setValue($this->registry['field_values'][$field->getId()]);
        }

        $this->registry['fields'][] = $field;

        return $this;
    }