Java program : Abstraction by using Interface

interface Inter
{
    void m1();
    void m2();
    void m3();

}
class ChildInter implements Inter
{
    public void m1()
    {System.out.println("m1");}
    public void m2(){}
    public void m3(){}
   
    public static void main(String[] args)
    {
        ChildInter ci=new ChildInter();
        ci.m1();
    }

}

Thanks
Happy programming!