java重复调用一个类的方法

package com.fc.test;

/*
 * 看极光推送的服务器端的JDK源码
 * 觉得比较好的，原来可以这样玩
 */
public class Test {

    public Test() {

    }

    public static void main(String args[]) {
        int x = new Test2()
                    .toT()
                    .toT2()
                    .toT3()
                    .toT4()
                    .getI();
        
        System.out.println(x);
    }

    public static class Test2 {

        private int i = 0;

        public Test2() {

        }

        public Test2 toT() {
            System.out.println("Test2 ----->>>  toT()");
            i++;
            return this;
        }

        public Test2 toT2() {
            System.out.println("Test2 ----->>>  toT2()");
            i++;
            return this;
        }

        public Test2 toT3() {
            System.out.println("Test2 ----->>>  toT3()");
            i++;
            return this;
        }

        public Test2 toT4() {
            System.out.println("Test2 ----->>>  toT4()");
            i++;
            return this;
        }

        public void setI(int i) {
            this.i = i;
        }

        public int getI() {
            return this.i;
        };
    }
}