Method add

patterns/TypeMap.java:13–17

(T o)

  public final Map<Class, List<T>> map =
    new HashMap<>();
  public void add(T o) {
    Class type = o.getClass();
    map.computeIfAbsent(type,
      k -> new ArrayList<T>()).add(o);
  }
  public Stream<List<T>> values() {
    return map.values().stream();
  }