docs: public static <T> Predicate<T> in(final Iterable<T> it) {
      return new Predicate<T>() {
        @Override
        public boolean apply(T obj) {
          for (T elem : it) {
            if (Objects.equal(elem, obj)) {
              return true;
            }
          }
          return false;
        }
      };
    }