void perform() {
      VirtualFile toSelect = getFileToSelect();
      List<OrderRoot> roots = selectRoots(toSelect);
      if (roots.isEmpty()) return;

      final List<OrderRoot> attachedRoots = attachFiles(roots);
      final OrderRoot first = ContainerUtil.getFirstItem(attachedRoots);
      if (first != null) {
        myLastChosen = first.getFile();
      }
      fireLibraryChanged();
      IdeFocusManager.getGlobalInstance().doWhenFocusSettlesDown(() -> IdeFocusManager.getGlobalInstance().requestFocus(myTree, true));
    }
void perform()