private static Navigatable @Nullable [] extractNavigatables(@NotNull List<MavenSimpleNode> selectedNodes) {
    final List<Navigatable> navigatables = new ArrayList<>();
    for (MavenSimpleNode each : selectedNodes) {
      Navigatable navigatable = each.getNavigatable();
      if (navigatable != null) navigatables.add(navigatable);
    }
    return navigatables.isEmpty() ? null : navigatables.toArray(Navigatable.EMPTY_NAVIGATABLE_ARRAY);
  }
private static Navigatable @Nullable [] extractNavigatables(@NotNull List<MavenSimpleNode> selectedNodes)