Review

class DocFieldConsumers {
  public void flush(Map threadsAndFields, SegmentWriteState state) throws IOException {

    Map oneThreadsAndFields = new HashMap();
    Map twoThreadsAndFields = new HashMap();

    Iterator it = threadsAndFields.entrySet().iterator();
    while(it.hasNext()) {

      Map.Entry entry = (Map.Entry) it.next();

      DocFieldConsumersPerThread perThread = (DocFieldConsumersPerThread) entry.getKey();

      Collection fields = (Collection) entry.getValue();

      Iterator fieldsIt = fields.iterator();
      Collection oneFields = new HashSet();
      Collection twoFields = new HashSet();
      while(fieldsIt.hasNext()) {
        DocFieldConsumersPerField perField = (DocFieldConsumersPerField) fieldsIt.next();
        oneFields.add(perField.one);
        twoFields.add(perField.two);
      }

      oneThreadsAndFields.put(perThread.one, oneFields);
      twoThreadsAndFields.put(perThread.two, twoFields);
    }
    

    one.flush(oneThreadsAndFields, state);
    two.flush(twoThreadsAndFields, state);
  }

}