How many objects are eligible for garbage collection till flag

public class Test
{
    public static void main(String [] args)
    {
        Test obj1 = new Test();
        Test obj2 = m1(obj1);
        Test obj4 = new Test();
        obj2 = obj4;               //Flag
        doComplexStuff();
    }
    static Test m1(Test mx)
    {
        mx = new Test();
        return mx;
    }
}