code: private Chunk[] getScoringChunks(Chunk[] allChunks) {
      if (_preds == null)
        return allChunks;
      Chunk[] chks = new Chunk[allChunks.length - _preds.numCols()];
      System.arraycopy(allChunks, 0, chks, 0, chks.length);
      return chks;
    }
docs: scoring chunks are those chunks that make the input to one of the scoring functions