For blog comment

snippet.java

private Map<String, List<String>> traces = new HashMap<String, List<String>>();


  private void writeSummary(final List<String> headers) throws IOException {
    SortHandler<Integer> handler = new SortHandler<Integer>() {
      public int to() {
        return headers.size() - 1;
      }
      public void swap(int i, int j) {
        Collections.swap(headers, i, j);
      }
      public Integer get(int index) {
        String header = headers.get(index);
        return traces.get(headerKeys.get(header)).size();
      }
      public int compare(Integer a, Integer b) {
        return a.compareTo(b);
      }
    };
    handler.sort();
    
    ...
}