code: @SuppressWarnings({ "unchecked" })
      public static <V> Optional<V> get(Map<?, ?> map, Class<V> type,
              Serializable id) {
          return Optional
              .ofNullable((V) map.get(new TypedIdKey<>(type, id)));
      }
docs: Retrieves a value with the given type and id from the given map.
  
  @param <V> the value type
  @param map the map
  @param type the type
  @param id the id
  @return the associated value, if any