Package functions cannot be abstract?!

[Jonathan Levi]

Why in the world can abstract functions not be only visible to 
only a package?

I have a public abstract class which has private implementations. 
  Some abstract member functions are needed for use withing the 
package but should not be visible publicly.

What is the point of making this not possible?!  Is it more 
difficult to implement or is just a random limitation for the 
heck of it?

Do you have a recommendation on how to do what I am trying to do?

Thanks.

```
class Cls {
     package abstract void fun(string a){};
}
```
Error: function `onlineapp.A.a` package functions cannot be 
abstract