private function _fillSubFields(array &$aSubFields, array $aFirstField)
{
foreach ($aSubFields as &$_aSubField) {
$_aLabel = $this->getElement($_aSubField, 'label', $this->getElement($aFirstField, 'label', null));
$_aSubField = $this->uniteArrays($_aSubField, $aFirstField);
$_aSubField['label'] = $_aLabel;
}
}