private function buildSelectorForExcerpt($locale, &$additionalFields)
{
$excerptStructure = $this->structureManager->getStructure('excerpt');
$extension = $this->extensionManager->getExtension('', 'excerpt');
foreach ($excerptStructure->getProperties(true) as $property) {
$additionalFields[$locale][] = ['extension' => $extension, 'target' => 'excerpt', 'property' => $property->getName(), 'name' => $property->getName()];
}
}