code: public static void main(String[] args) {
      //TreeFactory tf = new LabeledScoredTreeFactory();
      Tree stringyTree = null;
      try {
        stringyTree = (new PennTreeReader(new StringReader("(S (VP (VBZ Try) (NP (DT this))) (. .))"), new LabeledScoredTreeFactory(new StringLabelFactory()))).readTree();
      } catch (IOException e) {
        // do nothing
      }
      System.out.println(stringyTree);
      Function<Tree, Tree> a = getLabeledTreeToCategoryWordTagTreeFunction();
      Tree adaptyTree = a.apply(stringyTree);
      System.out.println(adaptyTree);
      adaptyTree.percolateHeads(new CollinsHeadFinder());
      System.out.println(adaptyTree);
  
      Function<Tree, Tree> b = getLabeledTreeToStringLabeledTreeFunction();
      Tree stringLabelTree = b.apply(adaptyTree);
      System.out.println(stringLabelTree);
  
    }
docs: This method just tests the functionality of the included transformers.