code: public ObjectType createAnonymousObjectType(JSDocInfo info) {
      PrototypeObjectType type = new PrototypeObjectType(
          this, null, null, true /* anonymousType */);
      type.setPrettyPrint(true);
      type.setJSDocInfo(info);
      return type;
    }
docs: Create an anonymous object type.
  @param info Used to mark object literals as structs; can be {@code null}