public static MetadataUpdate fromJson(String json) {
    return JsonUtil.parse(json, MetadataUpdateParser::fromJson);
  }
@Test
  public void testSetCurrentSchemaFromJson() {
    String action = MetadataUpdateParser.SET_CURRENT_SCHEMA;
    int schemaId = 6;
    String json = String.format("{\"action\":\"%s\",\"schema-id\":%d}", action, schemaId);
    MetadataUpdate.SetCurrentSchema expected = new MetadataUpdate.SetCurrentSchema(schemaId);
    assertEquals(action, expected, MetadataUpdateParser.fromJson(json));
  }