/**
* Overridden to use _idFieldName by default.
*
* @param null $valueField
* @param string $labelField
* @param array $additional
* @return array
*/
protected function _toOptionArray($valueField = null, $labelField = 'name', $additional = [])
{
if ($valueField === null) {
$valueField = $this->getIdFieldName();
}
return parent::_toOptionArray($valueField, $labelField, $additional);
}