import java.util.function.Function;

public interface Printable {
    public String print(String s);
    public static void main(String[] args) {
        //Printable p = s -> "prefix "+s;
        Function<String, String> fn = p -> p +" from lambda";
        String result = fn.apply("test");
        System.out.println(result);
    }

}

What I mean is, fn.apply(“test”) seems unnecessary, since the only possible method is apply. So why not syntax like fn::(test) ?