docs: @Override
    public void serializeClassifier(String serializePath) {
      System.err.print("Serializing classifier to " + serializePath + "...");
  
      ObjectOutputStream oos = null;
      try {
        oos = IOUtils.writeStreamFromString(serializePath);
  
        oos.writeObject(labelIndices);
        oos.writeObject(classIndex);
        oos.writeObject(featureIndex);
        oos.writeObject(flags);
        oos.writeObject(featureFactory);
        oos.writeInt(windowSize);
        oos.writeObject(weights);
        // oos.writeObject(WordShapeClassifier.getKnownLowerCaseWords());
  
        oos.writeObject(knownLCWords);
  
        System.err.println("done.");
  
      } catch (Exception e) {
        System.err.println("Failed");
        e.printStackTrace();
        // don't actually exit in case they're testing too
        // System.exit(1);
      } finally {
        IOUtils.closeIgnoringExceptions(oos);
      }
    }