private static @NotNull Stream<TagNameSynchronizer> findSynchronizers(@Nullable Document document) {
    if (document == null || !WebEditorOptions.getInstance().isSyncTagEditing()) {
      return Stream.empty();
    }
    return EditorFactory.getInstance().editors(document, null)
      .map(editor -> editor.getUserData(SYNCHRONIZER_KEY))
      .filter(Objects::nonNull);
  }
private static @NotNull Stream<TagNameSynchronizer> findSynchronizers(@Nullable Document document)