@Test
public void toJSON() throws IOException {

  Handlebars handlebars = new Handlebars();
  handlebars.registerHelper("@json", Jackson2Helper.INSTANCE);
  Template template = handlebars.compileInline("{{@json this}}");
  CharSequence result = template.apply(new Blog("First Post", "..."));
  assertEquals("{\"title\":\"First Post\",\"body\":\"...\",\"comments\":[]}",
      result);
}