code: @Deprecated
    public void setDeltaFields(String... deltaFieldName) {
      setProp(ConfigurationKeys.EXTRACT_DELTA_FIELDS_KEY, Joiner.on(",").join(deltaFieldName));
    }
docs: Set delta fields.
  
  <p>
  The order of delta fields does not matter.
  </p>
  
  @param deltaFieldName delta field names
  @deprecated It is recommended to set delta fields in {@code WorkUnit} instead of {@code Extract}.