docs: private boolean addExtractorOrDynamicValueAsFieldWriter(List<Object> list, FieldExtractor extractor, String header, boolean commaMightBeNeeded) {
          if (extractor != null) {
              String head = header;
              if (commaMightBeNeeded) {
                  head = "," + head;
              }
              list.add(new FieldWriter(head, extractor));
              return true;
          }
          return commaMightBeNeeded;
      }