private void clearUnusedHighlighters() {
    myHighlighters.removeIf(h -> {
      if (h.getUserData(MARKER_USED) == null) {
        removeHighlighterWithDependent(h);
        return true;
      }
      else {
        h.putUserData(MARKER_USED, null);
        return false;
      }
    });
  }
private void clearUnusedHighlighters()