public static MetadataUpdate fromJson(String json) {
    return JsonUtil.parse(json, MetadataUpdateParser::fromJson);
  }
@Test
  public void testSetCurrentViewVersionFromJson() {
    String action = MetadataUpdateParser.SET_CURRENT_VIEW_VERSION;
    String json = String.format("{\"action\":\"%s\",\"view-version-id\":23}", action);
    MetadataUpdate expected = new MetadataUpdate.SetCurrentViewVersion(23);
    assertEquals(action, expected, MetadataUpdateParser.fromJson(json));
  }