title: fetchAssetsWithLocalIdentifiers:options: My Photo Stream not working
body: <p>I've encountered weird thing with Photos Framework: 
  If I fetch PHAssets from PHAssetCollection of a subtype <code>PHAssetCollectionSubtypeAlbumMyPhotoStream</code>, I can enumerate them and get for every PHAsset its thumbnail and everything. </p>
  
  <p>But if I try to get those My Photo Stream assets by their <code>localIdentifier</code> (meanwhile stored in db) via <code>fetchAssetsWithLocalIdentifiers:options:</code> I get no results. Assets from other albums are ok, even those from iCloud (<code>PHAssetCollectionSubtypeAlbumCloudShared</code>).</p>
  
  <p>Anyone has any ideas why it is so? </p>