Method references

So far, all our functions were short one-liners. Here is another example:

Supplier<Integer> input = () -> 3;

Predicate<Integer> checkValue = d -> d < 5;

Function<Integer, Double> calculate = i -> i * 5.0;

Consumer<Double> printResult = d -> System.out.println(

                                               "Result: " + d);

if(checkValue.test(input.get())){

    printResult.accept(calculate.apply(input.get()));

} else {

    System.out.println("Input " + input.get() + 

                        ...