Swift extensions and inheritance

playground

import UIKit

protocol Thing {
    func name() -> String
}

protocol God {
    func talk() -> String
}

class Base : Thing {
    func a() -> String {
        return "Base A"
    }
    
    func name() -> String {
        return "base name"
    }
}

extension Base : God {
    func talk() -> String {
        return "base talk"
    }
}

class Child : Base {
    override func a() -> String {
        return "child A"
    }
    
    override func name() -> String {
        return "child name"
    }
    
    override func talk() -> String {
        return "child talk"
    }
}

let base = Base()
base.a()
base.name()
base.talk()

let child = Child()
child.a()
child.name()
child.talk()

Nice example. I see you are strong in this. Could you please help me with question below?
I have 2 classes and 1 extension. Like following:

class A // Scene of sprite kit.
{
  var sprite: SKSpriteNode!
  addSprite() // this method invokes and adds sprite normally
}
extension A
{
  func addSprite() {
    sprite = SKSprite(image)
    // sets all positions and size, z position as well
   addChild(sprite)
  }
}
class B: A // B is a simple class
{
  if condition {
     super.addSprite() // this method also invokes, does the things but on the scene of class A no sprite. 
  }
}

I believe here is something wrong with inheritance but I don't know what.
If you have some thoughts could you please share it with me.
Thank you in advance.