code: public static Map dotAssoc(final Map map, final String pathString, final Object value) {
          return dotAssoc(map, map.getClass(), pathString, value);
      }
docs: Associates new value in map placed at path. New nodes are created with same class as map if needed.
  @param map subject original map
  @param pathString nodes to walk in map path to place new value
  @param value new value
  @return original map