Get value from inherited class' function while executing the same overrided function?

[Deukalion]

Hey.

I have a class that implements an interface, that class is later inherited from by a few other classes. The first class has a "basic function" that returns a value. How can I get that value from the "parent" class' function when I override it?

interface A
{

   String getData();

}

class B : A
{
   public class B()
   {
    }

   public String getData()
   {
       return "Hey";
   }
}

class C : B
{
   public class C()
  {
  }

  public String getData()
  {
      return Parent->getData() + "\nHello";
  }
}

So when I execute:

B b = new B();
b.getData();
OUTPUT: "Hey";

C c = new C();
c.getData();
OUTPUT = "Hey Hello";

I'm wondering this, because I'm trying to inherit classes that have specific "properties" for that class. Say we have an animal -> mammal -> dog, Animal is just the "shell", all "mammals" have some properties that are unique, and later on a Dog has different properties than a Cat but they're still bot mammals and should retrieve the Mammals properties or likewise...

Any ideas?