public function setAssetCollections(Collection $assetCollections)
    {
        $this->lastModified = new \DateTime();
        foreach ($this->assetCollections as $existingAssetCollection) {
            $existingAssetCollection->removeAsset($this);
        }
        foreach ($assetCollections as $newAssetCollection) {
            $newAssetCollection->addAsset($this);
        }
        foreach ($this->assetCollections as $assetCollection) {
            if (!$assetCollections->contains($assetCollection)) {
                $assetCollections->add($assetCollection);
            }
        }
        $this->assetCollections = $assetCollections;
    }