anchor.diff:    }
   
     Future<ReviewInfo> reviewInfo(int review) async {
  -    return ReviewInfo.fromDocument(
  -        await _firestoreService.fetchReviewInfo(review))
  -      ..setPatchsets(await _firestoreService.fetchPatchsetInfo(review));
  +    final doc = await _firestoreService.fetchReviewInfo(review);
  +    if (doc.exists) {
  +      return ReviewInfo.fromDocument(doc)
  +        ..setPatchsets(await _firestoreService.fetchPatchsetInfo(review));
  +    } else {
  +      return ReviewInfo(review, "No results received yet for CL $review", []);
  +    }
     }
   }
   
  
positive.code:   int review;
    String title;
    List<Patchset> patchsets;
  
    ReviewInfo.fromDocument(DocumentSnapshot doc) {
      final data = doc.data();
  
negative.code: 
    Future<List<Change>> changes(ReviewInfo changeInfo, int patch) async {
      final patchsets = changeInfo.patchsets;
      if (patchsets.length < patch) return [];
      // Patchset numbers start at 1, not 0.
      int patchsetGroup = patchsets[patch - 1].patchsetGroup;
      // Workaround while [ ... await foo() ] does not work in dartdevc.
  