code: public TwoDimTable createCentroidStatsTable() {
      if (_size == null || _withinss == null)
        return null;
      List<String> colHeaders = new ArrayList<>();
      List<String> colTypes = new ArrayList<>();
      List<String> colFormat = new ArrayList<>();
  
      colHeaders.add("Centroid"); colTypes.add("long"); colFormat.add("%d");
      colHeaders.add("Size"); colTypes.add("double"); colFormat.add("%.5f");
      colHeaders.add("Within Cluster Sum of Squares"); colTypes.add("double"); colFormat.add("%.5f");
  
      final int K = _size.length;
      assert(_withinss.length == K);
  
      TwoDimTable table = new TwoDimTable(
              "Centroid Statistics", null,
              new String[K],
              colHeaders.toArray(new String[0]),
              colTypes.toArray(new String[0]),
              colFormat.toArray(new String[0]),
              "");
      for (int k =0; k<K; ++k) {
        int col = 0;
        table.set(k, col++, k+1);
        table.set(k, col++, _size[k]);
        table.set(k, col, _withinss[k]);
      }
      return table;
    }
docs: Populate TwoDimTable from members _size and _withinss
  @return TwoDimTable