docs: public static <K /*>>> extends @NonNull Object*/, V /*>>> extends @NonNull Object*/>
        void checkMapElementNotNull(Map<K, V> map, @javax.annotation.Nullable Object errorMessage) {
      for (Map.Entry<K, V> entry : map.entrySet()) {
        if (entry.getKey() == null || entry.getValue() == null) {
          throw new NullPointerException(String.valueOf(errorMessage));
        }
      }
    }