docs: private boolean collectSpan() throws IOException {
      if (lastSpan) {
        return false;
      } else if (spans.nextStartPosition() == NO_MORE_POSITIONS) {
        lastSpan = true;
        return false;
      } else {
        queueSpans.add(new Match(spans.startPosition(), spans.endPosition()));
        lastStartPosition = spans.startPosition();
        return true;
      }
    }