  @Test
  public void testAddSketches() {

    TableReporter.Sketches sketches = new TableReporter.Sketches();
    final int rows = 10;
    final int columns = 3;
    final int versions = 2;
    for (int i = 0; i < rows; i++) {
      TableReporter.processRowResult(Result.create(makeCells(Bytes.toBytes(i), columns, versions)), sketches);
    }
    sketches.print();
    TableReporter.Sketches sketches2 = new TableReporter.Sketches();
    for (int i = 0; i < rows; i++) {
      TableReporter.processRowResult(Result.create(makeCells(Bytes.toBytes(i), columns, versions)), sketches2);
    }
    sketches2.print();
    TableReporter.AccumlatingSketch accumlator = new TableReporter.AccumlatingSketch();
    accumlator.add(sketches);
    accumlator.add(sketches2);
    TableReporter.Sketches sum = accumlator.get();

    // Just check the column counts. Should be 2.
    double [] columnCounts = sum.columnCountSketch.getQuantiles(new double [] {1});
    assertEquals(columnCounts.length, 1);
    assertEquals((int)columnCounts[0], columns * versions);
    sum.print();
  }