code: public static final void postProcessDuplicatedSpans(final List<Span> preList,
        final Span[] postList) {
      final List<Span> duplicatedSpans = new ArrayList<Span>();
      for (final Span span1 : preList) {
        for (final Span span2 : postList) {
          if (span1.contains(span2)) {
            duplicatedSpans.add(span1);
          } else if (span2.contains(span1)) {
            duplicatedSpans.add(span1);
          }
        }
      }
      preList.removeAll(duplicatedSpans);
    }
docs: Removes spans from the preList if the span is contained in the postList.
  
  @param preList
  the list of spans to be post-processed
  @param postList
  the list of spans to do the post-processing