static @NotNull Set<String> getDefaultPackagesNames(@NotNull Project project) {
    return CachedValuesManager.getManager(project)
      .getCachedValue(project, 
                      () -> CachedValueProvider.Result.create(ContainerUtil.map2Set(getDefaultPackages(project), PsiPackage::getName), 
                                                              PsiModificationTracker.MODIFICATION_COUNT));
  }
static @NotNull Set<String> getDefaultPackagesNames(@NotNull Project project)