/**
* @param SubField $subField
*
* @return string
*/
private function convertSubField(SubField $subField)
{
$result = File_MARC::SUBFIELD_INDICATOR . $subField->getCode() . $subField->getContent();
return (string) $result;
}
/**
* @param SubField $subField
*/
public function addSubField(SubField $subField)
{
$this->subField[$subField->getCode()] = $subField;
}