JSONBuilder { @Override public String toString() { return JsonUtil.toJson(data); }  JSONBuilder put(String key, @Nullable Object value); JSONBuilder put(String key, @Nullable Instant value); JSONBuilder put(String key, @Nullable Duration value); JSONBuilder putBase64(String key, byte[] data); JSONBuilder putKey(String key, PublicKey publickey); JSONBuilder object(String key); JSONBuilder array(String key, Collection<?> values); Map<String, Object> toMap(); JSON toJSON(); @Override String toString();  }
@Test public void testEmpty() { JSONBuilder cb = new JSONBuilder(); assertThat(cb.toString(), is("{}")); }