@TestOnly
  public void validateState() {
    LOG.assertTrue(!DocumentUtil.isInsideSurrogatePair(myEditor.getDocument(), getOffset()));
    LOG.assertTrue(!DocumentUtil.isInsideSurrogatePair(myEditor.getDocument(), getSelectionStart()));
    LOG.assertTrue(!DocumentUtil.isInsideSurrogatePair(myEditor.getDocument(), getSelectionEnd()));
  }
@TestOnly
  public void validateState()