code: public static <T> T dotGetNullable(final Map map, final Class<T> clazz, final String pathString) {
          if (pathString == null || pathString.isEmpty()) {
              throw new IllegalArgumentException(PATH_MUST_BE_SPECIFIED);
          }
          if (!pathString.contains(SEPARATOR)) {
              return (T) map.get(pathString);
          }
          final Object[] path = pathString.split(SEPARATOR_REGEX);
          return MapApi.getUnsafe(map, clazz, path);
      }
docs: Walks by map's nodes and extracts optional value of type T.
  @param <T> value type
  @param clazz type of value
  @param map subject
  @param pathString nodes to walk in map
  @return value of type T