Call the instance

main.java

public class Main {
    public static void main(String[] args){

        Singleton new1 =  Singleton.getInstance("John", 30);
        Singleton new2 =  Singleton.getInstance("Doe", 28);

        System.out.println("new 1 "+ new1.getName()+" "+ new1.getAge());
        System.out.println("new 2 "+ new2.getName()+" "+ new2.getAge());
    }
}