code: static List<List<Segment>> readSegmentLinesBeforeRendering(
              AbstractContainerSegment container) {
          List<List<Segment>> lines = new ArrayList<>();
          List<Segment> currentLine = new ArrayList<>();
  
          for (Segment segment : container) {
              if (!SegmentType.LINE_SEPARATOR.equals(segment.getType())) {
                  currentLine.add(segment);
              } else {
                  // New line separator - flush the line
                  currentLine.add(segment);
                  lines.add(currentLine);
                  currentLine = new ArrayList<>();
              }
          }
          // Add the last line manually - there is no line separator to trigger
          // flush
          if (!currentLine.isEmpty()) {
              lines.add(currentLine);
          }
          return lines;
      }
docs: Read segment lines before rendering.
  
  @param container
  @return