private static @Nullable String getMenuId(Collection<? extends ExternalSystemNode> nodes) {
        String id = null;
        for (ExternalSystemNode node : nodes) {
          String menuId = node.getMenuId();
          if (menuId == null) {
            return null;
          }
          if (id == null) {
            id = menuId;
          }
          else if (!id.equals(menuId)) {
            return null;
          }
        }
        return id;
      }
private static @Nullable String getMenuId(Collection<? extends ExternalSystemNode> nodes)