private static @Nullable Set<PyRequirement> getRequirementsInclTransitive(@NotNull PyPackageManager packageManager, @NotNull Module module) {
    final List<PyRequirement> requirements = getListedRequirements(packageManager, module);
    if (requirements == null) return null;
    if (requirements.isEmpty()) return Collections.emptySet();

    final List<PyPackage> packages = packageManager.getPackages();
    if (packages == null) return null;

    final Set<PyRequirement> result = new HashSet<>(requirements);
    result.addAll(getTransitiveRequirements(packages, requirements, new HashSet<>()));
    return result;
  }
private static @Nullable Set<PyRequirement> getRequirementsInclTransitive(@NotNull PyPackageManager packageManager, @NotNull Module module)