@RequiresEdt
  protected void installInnerHighlighters() {
    assert myInnerHighlighters.isEmpty();

    createInnerHighlighter(ThreeSide.BASE);
    if (isChange(Side.LEFT)) createInnerHighlighter(ThreeSide.LEFT);
    if (isChange(Side.RIGHT)) createInnerHighlighter(ThreeSide.RIGHT);
  }
@RequiresEdt
  protected void installInnerHighlighters()