PHP change method/function visibility

I am trying to write a PHP class in which I change the visibility of a few methods from protected to public. I believe I remember you can do this in C++, but I did a few searches and I am not coming up with anything for that in PHP. Does anyone know if this is even possible in PHP?

For example, suppose this class:

 class ABC {
     protected function foo() {
          // Do something
     }
  }

  class DEG extends ABC {
      // can I make foo public now?
  }