Doctrine\ODM\MongoDB\SchemaManager::deleteIndexes PHP Method

    public function deleteIndexes()
    {
        foreach ($this->metadataFactory->getAllMetadata() as $class) {
            if ($class->isMappedSuperclass || $class->isEmbeddedDocument || $class->isQueryResultDocument) {
                continue;
            }
            $this->deleteDocumentIndexes($class->name);
        }
    }

 protected function processIndex(SchemaManager $sm)
 {
     $sm->deleteIndexes();
 }