code: public static <T> Optional<T> dotGetNullableOptional(
              final Map map, final String pathString, final Class<T> clazz
      ) {
          return dotGetNullable(map, Optional.class, pathString);
      }
docs: Get optional value by path.
  @param <T> optional value type
  @param clazz type of value
  @param map subject
  @param pathString nodes to walk in map
  @return value