KeyValue compact(final ArrayList<KeyValue> row,
      List<Annotation> annotations,
      List<HistogramDataPoint> histograms) {
    final KeyValue[] compacted = { null };
    compact(row, compacted, annotations, histograms);
    return compacted[0];
  }
KeyValue compact ( final ArrayList < KeyValue > row , List < Annotation > annotations , List < HistogramDataPoint > histograms ) { final KeyValue [ ] compacted = { null } ; compact ( row , compacted , annotations , histograms ) ; return compacted [ 0 ] ; }
Compacts a row into a single {@link KeyValue}.
@param row The row containing all the KVs to compact.
Must contain at least one element.
@return A compacted version of this row.