public function deleteDocumentIndexes($documentName)
{
$class = $this->dm->getClassMetadata($documentName);
if ($class->isMappedSuperclass || $class->isEmbeddedDocument || $class->isQueryResultDocument) {
throw new \InvalidArgumentException('Cannot delete document indexes for mapped super classes, embedded documents or query result documents.');
}
$this->dm->getDocumentCollection($documentName)->deleteIndexes();
}