final String name;

    ConstructorDoesNotAcceptNull(String name) {
      this.name = checkNotNull(name);
    }
  }

  static class ConstructorParameterNotInstantiable {
    public ConstructorParameterNotInstantiable(@SuppressWarnings("unused") NotInstantiable x) {}
  }

  static class ConstructorParameterMapOfNotInstantiable {
    private final Map<NotInstantiable, NotInstantiable> m;