static <T> @NotNull Map<String, T> getOrCreateMap(@NotNull Map<String, Map<String, T>> resources, @Nullable String version) {
    version = Strings.notNullize(version, DEFAULT_VERSION);
    return resources.computeIfAbsent(version, __ -> new HashMap<>());
  }
static <T> @NotNull Map<String, T> getOrCreateMap(@NotNull Map<String, Map<String, T>> resources, @Nullable String version)