code: private List<String> extractTagsAndResetLastTagsLineField() {
          String tags = lastTagsLine;
          List<String> result = extractTags(tags);
          resetLastTagsLine();
          return result;
      }
docs: Extracts the tags from the lastTagsLine field before setting it to null.
  
  @return the tags or null if lastTagsLine is null.