Doctrine\ODM\MongoDB\Proxy\ProxyFactory::createInitializer PHP Method

    private function createInitializer(BaseClassMetadata $classMetadata, DocumentPersister $documentPersister, ReflectionProperty $reflectionId)
    {
        if ($classMetadata->getReflectionClass()->hasMethod('__wakeup')) {
            return function (BaseProxy $proxy) use($documentPersister, $reflectionId) {
                $proxy->__setInitializer(null);
                $proxy->__setCloner(null);
                if ($proxy->__isInitialized()) {
                    return;
                }
                $properties = $proxy->__getLazyProperties();
                foreach ($properties as $propertyName => $property) {
                    if (!isset($proxy->{$propertyName})) {
                        $proxy->{$propertyName} = $properties[$propertyName];
                    }
                }
                $proxy->__setInitialized(true);
                $proxy->__wakeup();
                $id = $reflectionId->getValue($proxy);
                if (null === $documentPersister->load(array('_id' => $id), $proxy)) {
                    if (!$this->lifecycleEventManager->documentNotFound($proxy, $id)) {
                        throw DocumentNotFoundException::documentNotFound(get_class($proxy), $id);
                    }
                }
                if ($proxy instanceof NotifyPropertyChanged) {
                    $proxy->addPropertyChangedListener($this->uow);
                }
            };
        }
        return function (BaseProxy $proxy) use($documentPersister, $reflectionId) {
            $proxy->__setInitializer(null);
            $proxy->__setCloner(null);
            if ($proxy->__isInitialized()) {
                return;
            }
            $properties = $proxy->__getLazyProperties();
            foreach ($properties as $propertyName => $property) {
                if (!isset($proxy->{$propertyName})) {
                    $proxy->{$propertyName} = $properties[$propertyName];
                }
            }
            $proxy->__setInitialized(true);
            $id = $reflectionId->getValue($proxy);
            if (null === $documentPersister->load(array('_id' => $id), $proxy)) {
                if (!$this->lifecycleEventManager->documentNotFound($proxy, $id)) {
                    throw DocumentNotFoundException::documentNotFound(get_class($proxy), $id);
                }
            }
            if ($proxy instanceof NotifyPropertyChanged) {
                $proxy->addPropertyChangedListener($this->uow);
            }
        };
    }