Sample code to manually call Garbage collector

package funds;
    class Student
    {
        int num=10;
        String name="laxman";
    }
public class GCDemo {
    public static void main(String arg[])
    {
        //nullifying reference varable
        Student s1=new Student();
        s1=null;  // destructed by GarbageCollector
        
        // Reassigning the reference variable
        Student s2=new Student();
        Student s3=new Student();
        s1=s2;  // s1 pointed object destructed by GarbageCollector
        
    }
}