public void serialize(@NotNull Element indentOptionsElement, @Nullable IndentOptions defaultOptions) {
      SerializationFilter filter = null;
      if (defaultOptions != null) {
        //noinspection deprecation
        filter = new SkipDefaultValuesSerializationFilters() {
          @Override
          protected void configure(@NotNull Object o) {
            if (o instanceof IndentOptions) {
              ((IndentOptions)o).copyFrom(defaultOptions);
            }
          }
        };
      }
      XmlSerializer.serializeObjectInto(this, indentOptionsElement, filter);
    }
public void serialize(@NotNull Element indentOptionsElement, @Nullable IndentOptions defaultOptions)