/**
     * This method uses a SplitRecord as the criertion to partition the given EmitterSet into two
     * subsets.
     *
     * @param split the plit record dicatating how to split
     */
    private EmitterSet[] makeSplit(SplitRecord split) {
      int arg = split.argument;
      ArgumentType test = split.test;
      EmitterSet yes = new EmitterSet();
      EmitterSet no = new EmitterSet();
      Iterator<EmitterDescriptor> i = emitters.iterator();
      while (i.hasNext()) {
        EmitterDescriptor ed = (EmitterDescriptor) i.next();
        if (ed.argMatchesEncoding(arg, test)) {
          yes.add(ed);
        } else {
          no.add(ed);
        }
      }

      return new EmitterSet[] {yes, no};
    }