public SufficientStats(SingletonFeatureFlock flock, bool hasWeights)
     : base(flock.Count)
 {
     Contracts.AssertValue(flock);
     _flock = flock;
     _hist  = new FeatureHistogram(_flock._bins, _flock._binUpperBounds.Length, hasWeights);
 }
 public Indexer(SingletonFeatureFlock flock)
 {
     Contracts.AssertValue(flock);
     _flock   = flock;
     _indexer = _flock.GetIndexer(0);
 }