// functional/TransformFunction.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
import java.util.function.*;

class I {
 @Override
 public String toString() { return "I"; }
}

class O {
 @Override
 public String toString() { return "O"; }
}

public class TransformFunction {
 static Function<I,O> transform(Function<I,O> in) {
 return in.andThen(o -> {
 System.out.println(o);
 return o;
 });
 }
 public static void main(String[] args) {
 Function<I,O> f2 = transform(i -> {
 System.out.println(i);
 return new O();
 });
 O o = f2.apply(new I());
 }
}
/* Output:
I
O
*/