code: public function createDocument(ObjectManager $manager, object $object) : ?Document {
  		if(!$this->isIndexable($object))
  			return null;
  		$document = $this->searchService->createEmptyDocumentFromEntity($object);
  		$index = $this->fillDocument($document, $object);
  		if($index === false)
  			return null;
  		
  		return $document;
  	}
docs: {@inheritDoc}
  @see \StingerSoft\EntitySearchBundle\Services\Mapping\EntityToDocumentMapperInterface::createDocument()