protected void syncElement(DirDiffElementImpl element) {
    final DirDiffOperation operation = element.getOperation();
    if (operation == null) return;
    switch (operation) {
      case COPY_TO -> performCopyTo(element);
      case COPY_FROM -> performCopyFrom(element);
      case DELETE -> performDelete(element);
      case MERGE, EQUAL, NONE -> {
      }
    }
  }
protected void syncElement(DirDiffElementImpl element)