public static void main(String[] args) {
Function<Integer, Integer> plus = i -> i + 1;
Function<Integer, Integer> mult = i -> i * i;
System.out.println("F1:" + plus.apply(1)); // 结果2
System.out.println("F2:" + mult.compose(plus).apply(3)); // 等于mult.apply(plus.apply(2)), 结果16
System.out.println("F3:" + mult.andThen(plus).apply(2)); // 等于plus.apply(mult.apply(2)), 结果5
}