// for stuff like #1000351

static class LMap extends LearnerImpl {
  static boolean debug;
  Map<String, String> map = new TreeMap<String, String>();

  public void processInOut(Object _in, Object _out) {
    List<String> in = cast _in;
    List<String> out = cast _out;
    
    if (in.size() != out.size()) fail();
    
    for (int i = 0; i < in.size(); i++) {
      String a = in.get(i), b = out.get(i);
      if (!a.equals(b))
        map.put(a, b);
    }
  }
  
  public Object processIn(Object _in) {
    List<String> in = cast _in;
    new List<String> out;
    for (int i = 0; i < in.size(); i++) {
      String a = in.get(i), b = map.get(a);
      out.add(b != null ? b : a);
    }
    return out;
  }
}

Began life as a copy of #1000485