It has practical value, let say you have something that caches the result of a lambda

  record Cache<T, U>(Function<T, U> function) {
    U get(T value) { ... }
  }

you can use it that way

  var cache = new Cache<Integer, Integer>(v -> v + 1);
  var result = cache.get(3);

with that settings, how do you specify a lambda which is recursive ? and how can you cache the intermediary steps if you can change the signature of get() ?