Java chain result functional way

Chain.java

public static void main(String[] args){

  int i = ((ThenResult<String>) ()-> "1")
          .then(s->Integer.parseInt(s))
          .result()

}

public interface ThenResult<T> {
		T result();

		default <U> ThenResult<U> then(Function<T, U> mapper) {
			return () -> mapper.apply(ThenResult.this.result());
		}
	}