@JsonProperty("type")
  public FSTType getFstType() {
    return _fstType;
  }
@Test
  public void withEmptyConf()
      throws JsonProcessingException {
    String confStr = "{}";
    FstIndexConfig config = JsonUtils.stringToObject(confStr, FstIndexConfig.class);

    assertFalse(config.isDisabled(), "Unexpected disabled");
    assertNull(config.getFstType(), "Unexpected type");
  }