code: public void call(String name) throws IOException {
          writer.write(generator.toJson(Collections.singletonMap(name, Collections.emptyMap())));
      }
docs: The empty args call will create a key whose value will be an empty JSON object:
  <pre class="groovyTestCase">
  new StringWriter().with { w {@code ->}
  def json = new groovy.json.StreamingJsonBuilder(w)
  json.person()
  
  assert w.toString() == '{"person":{}}'
  }
  </pre>
  
  @param name The name of the empty object to create
  @throws IOException