Static Binding in java

class A
{
public void hello()
{
System.out.println("hello in A");
}
}
class B extends A
{
public void hello()
{
System.out.println("hello in B");
}
}
class C
{
public static void main(String... args)
{
A a = new B();
a.hello();
}
}

hello in B

public class StaticBindingTest {
 
    public static void main(String args[])  {
       Collection c = new HashSet();
       StaticBindingTest et = new StaticBindingTest();
       et.sort(c);
     
    }
   
    //overloaded method takes Collection argument
    public Collection sort(Collection c){
        System.out.println("Inside Collection sort method");
        return c;
    }
 
   
   //another overloaded method which takes HashSet argument which is sub class
    public Collection sort(HashSet hs){
        System.out.println("Inside HashSet sort method");
        return hs;
    }
     
}

Output:
Inside Collection sort method

hows its possible i think in second case output will be 
"Inside HashSet sort method"
please correct me if i'm wrong